MCP48FVBXX 8-/10-/12-Bit Single/Dual Voltage Output Volatile Digital-to-Analog Converters with SPI Interface Features * Operating Voltage Range: - 2.7V to 5.5V - full specifications - 1.8V to 2.7V - reduced device specifications * Output Voltage Resolutions: - 8-bit: MCP48FVB0X (256 Steps) - 10-bit: MCP48FVB1X (1024 Steps) - 12-bit: MCP48FVB2X (4096 Steps) * Rail-to-Rail Output * Fast Settling Time of 7.8 s (typical) * DAC Voltage Reference Source Options: - Device VDD - External VREF pin (buffered or unbuffered) - Internal Band Gap (1.22V typical) * Output Gain Options: - Unity (1x) - 2x * Power-on/Brown-out Reset Protection * Power-Down Modes: - Disconnects output buffer (High Impedance) - Selection of VOUT pull-down resistors (100 k or 1 k) * Low Power Consumption: - Normal operation: <180 A (Single), 380 A (Dual) - Power-down operation: 650 nA typical * SPI Interface: - Supports `00' and `11' modes - Up to 20 MHz writes and 10 MHz reads - Input buffers support interfacing to low-voltage digital devices * Package Types: 10-lead MSOP * Extended Temperature Range: -40C to +125C Package Types MCP48FVBX1 MSOP Single VDD 1 2 VREF0 3 VOUT0 4 NC 5 CS MCP48FVBX2 MSOP Dual VDD CS VREF(1) VOUT0 VOUT1 Note 1: 1 2 3 4 5 10 SDI 9 SCK 8 SDO 7 VSS 6 LAT/HVC (1) Associated with both DAC0 and DAC1 General Description The MCP48FVBXX are Single- and Dual-channel 8-bit, 10-bit, and 12-bit buffered voltage output Digital-to-Analog Converters (DAC) with volatile memory and an SPI serial interface. The VREF pin, the device VDD or the internal band gap voltage can be selected as the DAC's reference voltage. When VDD is selected, VDD is connected internally to the DAC reference circuit. When the VREF pin is used, the user can select the output buffer's gain to be 1 or 2. When the gain is 2, the VREF pin voltage should be limited to a maximum of VDD/2. These devices have an SPI-compatible serial interface. Write commands are supported up to 20 MHz while read commands are supported up to 10 MHz. Applications * * * * * * 2015 Microchip Technology Inc. 10 SDI 9 SCK 8 SDO 7 VSS 6 LAT0/HVC Set Point or Offset Trimming Sensor Calibration Low-Power Portable Instrumentation PC Peripherals Data Acquisition Systems Motor Control DS20005466A-page 1 MCP48FVBXX MCP48FVBX1 Device Block Diagram (Single-Channel Output) Power-up/ Brown-out Control SDI Memory (32x16) SDO DAC0 (Vol) VREF (Vol) Power-down (Vol) Gain (Vol) Status (Vol) SCK SPI Serial Interface Module and Control Logic CS VREF1:VREF0 and PD1:PD0 VDD (1.22V) VREF0 + (1) - PD1:PD0 VSS VREF1:VREF0 Resistor Ladder VDD LAT0/HVC Gain PD1:PD0 and VREF1:VREF0 Band Gap VBG Op Amp VOUT0 PD1:PD0 100 k VSS 1 k VDD Note 1: If Internal Band Gap is selected, this buffer has a 2x gain. If the G bit = `1', this is a total gain of 4. DS20005466A-page 2 2015 Microchip Technology Inc. MCP48FVBXX MCP48FVBX2 Device Block Diagram (Dual-Channel Output) Power-up/ Brown-out Control Memory (32x16) DAC0 and DAC1 (Vol) VREF (Vol) Power-down (Vol) Gain (Vol) Status (Vol) SDI SDO SCK SPI Serial Interface Module and Control Logic CS VREF1:VREF0 and PD1:PD0 VREF Gain VDD PD1:PD0 and VREF1:VREF0 Band Gap VBG (1.22V) Op Amp VOUT0 PD1:PD0 + - (1) VSS VREF1:VREF0 LAT/HVC PD1:PD0 Resistor Ladder VDD VREF1:VREF0 and PD1:PD0 V 100 k VSS 1 k VDD Gain DD + - (1) PD1:PD0 VSS VREF1:VREF0 Resistor Ladder VDD VOUT1 PD1:PD0 100 k (1.22V) intVR1 Op Amp 1 k PD1:PD0 and VREF1:VREF0 Band Gap Note 1: If Internal Band Gap is selected, this buffer has a 2x gain, if the G bit = `1', this is a total gain of 4. 2015 Microchip Technology Inc. DS20005466A-page 3 MCP48FVBXX Control Interface DAC Output POR/BOR Setting (1) MCP48FVB01 Resolution (bits) Device # of Channels Device Features # of VREF Inputs 1 8 SPI 7Fh 1 Internal # of band LAT gap ? Inputs Yes 1 Memory Specified Operating Range (VDD) (2) RAM 1.8V to 5.5V MCP48FVB11 1 10 SPI 1FFh 1 Yes 1 RAM 1.8V to 5.5V MCP48FVB21 1 12 SPI 7FFh 1 Yes 1 RAM 1.8V to 5.5V MCP48FVB02 2 8 SPI 7Fh 1 Yes 1 RAM 1.8V to 5.5V MCP48FVB12 2 10 SPI 1FFh 1 Yes 1 RAM 1.8V to 5.5V MCP48FVB22 2 12 SPI 7FFh 1 Yes 1 RAM 1.8V to 5.5V MCP48FEB01 1 8 SPI 7Fh 1 Yes 1 EEPROM 1.8V to 5.5V MCP48FEB11 1 10 SPI 1FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP48FEB21 1 12 SPI 7FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP48FEB02 2 8 SPI 7Fh 1 Yes 1 EEPROM 1.8V to 5.5V MCP48FEB12 2 10 SPI 1FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP48FEB22 2 12 SPI 7FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP47FVB01 1 8 I2C 7Fh 1 Yes 1 RAM 1.8V to 5.5V 1FFh 1 Yes 1 RAM 1.8V to 5.5V 7FFh 1 Yes 1 RAM 1.8V to 5.5V MCP47FVB11 1 10 I2C MCP47FVB21 1 12 I2C MCP47FVB02 2 8 I2C 7Fh 1 Yes 1 RAM 1.8V to 5.5V MCP47FVB12 2 10 I2C 1FFh 1 Yes 1 RAM 1.8V to 5.5V MCP47FVB22 2 12 I2C 7FFh 1 Yes 1 RAM 1.8V to 5.5V MCP47FEB01 1 8 I2C 7Fh 1 Yes 1 EEPROM 1.8V to 5.5V 1FFh 1 Yes 1 EEPROM 1.8V to 5.5V 7FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP47FEB11 1 10 I2C MCP47FEB21 1 12 I2C MCP47FEB02 2 8 I2C 7Fh 1 Yes 1 EEPROM 1.8V to 5.5V MCP47FEB12 2 10 I2C 1FFh 1 Yes 1 EEPROM 1.8V to 5.5V 12 I2C 7FFh 1 Yes 1 EEPROM 1.8V to 5.5V MCP47FEB22 Note 1: 2: 2 Factory Default value. The DAC output POR/BOR value can be modified via the nonvolatile DAC output register(s) (available only on nonvolatile devices (MCP4XFEBXX)). Analog output performance specified from 2.7V to 5.5V. DS20005466A-page 4 2015 Microchip Technology Inc. MCP48FVBXX 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings () Voltage on VDD with respect to VSS ......................................................................................................... -0.6V to +6.5V Voltage on all pins with respect to VSS ............................................................................................... -0.6V to VDD+0.3V Input clamp current, IIK (VI < 0, VI > VDD, VI > VPP on HV pins) .......................................................................... 20 mA Output clamp current, IOK (VO < 0 or VO > VDD)...................................................................................................20 mA Maximum current out of VSS pin (Single) ..........................................................................................................50 mA (Dual)...........................................................................................................100 mA Maximum current into VDD pin (Single) ..........................................................................................................50 mA (Dual)...........................................................................................................100 mA Maximum current sourced by the VOUT pin ............................................................................................................20 mA Maximum current sunk by the VOUT pin..................................................................................................................20 mA Maximum current sunk by the VREF pin .................................................................................................................125 A Maximum input current source/sunk by SDI, SCK, and CS pins .............................................................................2 mA Maximum output current sunk by SDO Output pin .................................................................................................25 mA Total power dissipation (1) ....................................................................................................................................400 mW Package power dissipation (TA = +50C, TJ = +150C) MSOP-10 ..................................................................................................................................................490 mW ESD protection on all pins 4 kV (HBM) 400V (MM) 1.5 kV (CDM) Latch-Up (per JEDEC JESD78A) @ +125C ..................................................................................................... 100 mA Storage temperature ...............................................................................................................................-65C to +150C Ambient temperature with power applied ...............................................................................................-55C to +125C Soldering temperature of leads (10 seconds) ....................................................................................................... +300C Maximum Junction Temperature (TJ) .................................................................................................................... +150C Notice: Stresses above those listed under "Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Note 1: Power dissipation is calculated as follows: PDIS = VDD x {IDD - IOH} + {(VDD - VOH) x IOH} + (VOL x IOL) 2015 Microchip Technology Inc. DS20005466A-page 5 MCP48FVBXX DC CHARACTERISTICS DC Characteristics Parameters Supply Voltage Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. Typ. Max. Units Conditions VDD 2.7 -- 5.5 V 1.8 -- 2.7 V DAC operation (reduced analog specifications) and Serial Interface -- -- 1.7 V RAM retention voltage (VRAM) < VPOR VDD voltages greater than VPOR/BOR limit Ensure that device is out of reset. VDD Voltage (rising) to ensure device Power-on Reset VPOR/BOR VDD Rise Rate to ensure Power-on Reset VDDRR High-Voltage Commands Voltage Range (HVC pin) VHV VSS -- 12.5 V The HVC pin will be at one of three input levels (VIL, VIH or VIHH) (1) High-Voltage Input Entry Voltage VIHHEN 9.0 -- -- V Threshold for Entry into WiperLock Technology for compatibility with MCP48FEBxx devices High-Voltage Input Exit Voltage VIHHEX -- -- VDD + 0.8V V (Note 2) Power-on Reset to Output-Driven Delay TPORD -- 25 50 s VDD rising, VDD > VPOR V/ms (Note 3) Note 1 This parameter is ensured by design. Note 2 This parameter is ensured by characterization. Note 3 POR/BOR voltage trip point is not slope dependent. Hysteresis implemented with time delay. DS20005466A-page 6 2015 Microchip Technology Inc. MCP48FVBXX DC CHARACTERISTICS (CONTINUED) Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) DC Unless otherwise noted, all parameters apply across these specified operating ranges: Characteristics VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Supply Current Power-Down Current Sym. Min. Typ. Max. Units IDD -- -- 320 A -- -- 910 A -- -- 1.7 mA -- -- 510 A -- -- 1.1 mA 10 MHz (2) -- -- 1.85 mA 20 MHz -- -- 250 A -- -- 840 A -- -- 1.65 mA -- -- 380 A -- -- 970 A Serial Interface Active (Not High-Voltage Command) 10 MHz VRxB:VRxA = `10' (4) 20 MHz (2) VOUT is unloaded. 1 MHz (2) VREF = VDD = 5.5V Volatile DAC Register = 000h 10 MHz (2) -- -- 1.75 mA 20 MHz (2) -- -- 180 A -- -- 380 A -- -- 180 A -- -- 380 A -- 145 180 A -- 260 400 A -- 0.65 3.8 A IDDP Conditions Serial Interface Active (Not High-Voltage Command) 10 MHz (2) VRxB:VRxA = `01' (6) 20 MHz VOUT is unloaded, VDD = 5.5V (2) Volatile DAC Register = 000h 1 MHz Single 1MHz (2) Dual Single 1 MHz (2) (2) Dual Single Serial Interface Inactive (2) Dual (Not High-Voltage Command) VRxB:VRxA = `00' SCK = SDI = VSS VOUT is unloaded. Volatile DAC Register = 000h Single Serial Interface Inactive (2) Dual (Not High-Voltage Command) VRxB:VRxA = `11', VREF = VDD SCK = SDI = VSS VOUT is unloaded. Volatile DAC Register = 000h Single HVC = 12.5V (High-Voltage Command) Dual Serial Interface Inactive VREF = VDD = 5.5V, LAT/HVC = VIHH DAC registers = 000h VOUT pins are unloaded PDxB:PDxA = `01' (5) VOUT not connected Note 2 This parameter is ensured by characterization. Note 4 Supply current is independent of current through the resistor ladder in mode VRxB:VRxA = `10'. Note 5 The PDxB:PDxA = `01', `10', and `11' configurations should have the same current. Note 6 By design, this is the worst-case current mode. 2015 Microchip Technology Inc. DS20005466A-page 7 MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Parameters Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. Typ. Max. Units Resistor Ladder Resistance RL 100 140 180 k Resolution (# of Resistors and # of Taps) (see B.1 "Resolution") N Nominal VOUT Match (11) |VOUT - VOUTMEAN| /VOUTMEAN Conditions 1.8V VDD 5.5V VREF 1.0V (7) 256 1024 4096 Taps Taps Taps -- 0.5 1.0 % -- -- 1.2 % 8-bit 10-bit 12-bit No Missing Codes No Missing Codes No Missing Codes 2.7V VDD 5.5V (2) 1.8V (2) ppm/C Code = Mid-scale (7Fh, 1FFh or 7FFh) VOUT Tempco VOUT/T -- 15 -- (See B.19 "VOUT Temperature Coefficient" VREF VSS -- VDD V VREF pin 1.8V VDD 5.5V (1) Input Voltage Range Note 1 This parameter is ensured by design. Note 2 This parameter is ensured by characterization. Note 7 Resistance is defined as the resistance between the VREF pin (mode VRxB:VRxA = `10') to VSS pin. For dual-channel devices (MCP48FVBX2), this is the effective resistance of the each resistor ladder. The resistance measurement is that of the two resistor ladders measured in parallel. Note 11 Variation of one output voltage to mean output voltage. DS20005466A-page 8 2015 Microchip Technology Inc. MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units Zero-Scale Error (see B.5 "Zero-Scale Error (EZS)") (Code = 000h) EZS -- -- 0.75 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -- -- 3 2015 Microchip Technology Inc. 8-bit LSb VRxB:VRxA = `11', Gx = `0' VREF = VDD, No Load VRxB:VRxA = `00', Gx = `0' VDD = 5.5V, No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `10', Gx = `0', No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `11', Gx = `0', No Load LSb VRxB:VRxA = `01', Gx = `0', No Load LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -- -- 12 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -15 1.5 +15 LSb EOSD Offset Error (see B.8 "Offset Error Drift (EOSD)") -- 10 -- Offset Voltage VOSTC Temperature Coefficient Note 2 This parameter is ensured by characterization. Conditions 10-bit VRxB:VRxA = `11', Gx = `0' VREF = VDD, No Load VRxB:VRxA = `00', Gx = `0' VDD = 5.5V, No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `10', Gx = `0', No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `11', Gx = `0', No Load LSb VRxB:VRxA = `01', Gx = `0' No Load LSb 12-bit VRxB:VRxA = `11', Gx = `0' VREF = VDD, No Load VRxB:VRxA = `00', Gx = `0' VDD = 5.5V, No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `10', Gx = `0', No Load LSb VDD = 1.8V, VREF = 1.0V VRxB:VRxA = `11', Gx = `0', No Load LSb VRxB:VRxA = `01', Gx = `0' No Load mV VRxB:VRxA = `00' Gx = `0' No Load V/C DS20005466A-page 9 MCP48FVBXX DC CHARACTERISTICS (CONTINUED) Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) DC Unless otherwise noted, all parameters apply across these specified operating ranges: Characteristics VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units Full-Scale Error (see B.4 "Full-Scale Error (EFS)") EFS -- -- 4.5 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -- -- 18 LSb Note 2 8-bit Code = FFh, VRxB:VRxA = `11' Gx = `0', VREF = 2.048V, No Load Code = FFh, VRxB:VRxA = `10' Gx = `0', VREF = 2.048V, No Load LSb Code = FFh, VRxB:VRxA = `01' Gx = `0', VREF = 2.048V, No Load LSb Code = FFh, VRxB:VRxA = `00' No Load LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -- -- 70 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) This parameter is ensured by characterization. LSb DS20005466A-page 10 Conditions 10-bit Code = 3FFh, VRxB:VRxA = `11' Gx = `0', VREF = 2.048V, No Load Code = 3FFh, VRxB:VRxA = `10' Gx = `0', VREF = 2.048V, No Load LSb Code = 3FFh, VRxB:VRxA = `01' Gx = `0', VREF = 2.048V, No Load LSb Code = 3FFh, VRxB:VRxA = `00' No Load LSb 12-bit Code = FFFh, VRxB:VRxA = `11' Gx = `0', VREF = 2.048V, No Load Code = FFFh, VRxB:VRxA = `10' Gx = `0', VREF = 2.048V, No Load LSb Code = FFFh, VRxB:VRxA = `01' Gx = `0', VREF = 2.048V, No Load LSb Code = FFFh, VRxB:VRxA = `00' No Load 2015 Microchip Technology Inc. MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units Gain Error (see B.9 "Gain Error (EG)") (8) EG -1.0 0.1 +1.0 % of FSR 8-bit % of FSR 10-bit % of FSR 12-bit -1.0 -1.0 0.1 0.1 Gain-Error Drift (see G/C -- -3 B.10 "Gain-Error Drift (EGD)") Note 8 This gain error does not include offset error. 2015 Microchip Technology Inc. +1.0 +1.0 -- Conditions Code = 250, No Load VRxB:VRxA = `00' Gx = `0' Code = 1000, No Load VRxB:VRxA = `00' Gx = `0' Code = 4000, No Load VRxB:VRxA = `00' Gx = `0' ppm/C DS20005466A-page 11 MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units Integral Nonlinearity (see B.11 "Integral Nonlinearity (INL)") (10) INL -0.5 0.1 +0.5 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -1.5 0.4 +1.5 See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -6 1.5 +6 Note 2 Note 10 LSb Conditions 8-bit VRxB:VRxA = `10' (codes: 6 to 250) VDD = VREF = 5.5V VRxB:VRxA = `00', `01', `11' LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' LSb VRxB:VRxA = `10', `11' VREF = 1.0V, Gx = `1' LSb VDD = 1.8V VREF = 1.0V LSb LSb 10-bit VRxB:VRxA = `10' (codes: 25 to 1000) VDD = VREF = 5.5V VRxB:VRxA = `00', `01', `11' LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' LSb VRxB:VRxA = `10', `11' VREF = 1.0V, Gx = `1' LSb VDD = 1.8V VREF = 1.0V LSb 12-bit VRxB:VRxA = `10' (codes: 100 to 4000) VDD = VREF = 5.5V. VRxB:VRxA = `00', `01', `11' See Section 2.0, "Typical LSb (2) Performance Curves" See Section 2.0, "Typical LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' Performance Curves" (2) See Section 2.0, "Typical LSb VRxB:VRxA = `10', `11' (2) VREF = 1.0V, Gx = `1' Performance Curves" See Section 2.0, "Typical LSb VDD = 1.8V VREF = 1.0V Performance Curves" (2) This parameter is ensured by characterization. Code range dependent on resolution: 8-bit, codes 6 to 250; 10-bit, codes 25 to 1000; 12-bit, codes 100 to 4000. DS20005466A-page 12 2015 Microchip Technology Inc. MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Parameters Differential Nonlinearity (see B.12 "Differential Nonlinearity (DNL)")(10) Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. Typ. Max. Units DNL -0.25 0.0125 +0.25 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -0.5 0.05 +0.5 LSb See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) See Section 2.0, "Typical Performance Curves" (2) -1.0 0.2 +1.0 Note 2 Note 10 Conditions 8-bit VRxB:VRxA = `10' (codes: 6 to 250) VDD = VREF = 5.5V VRxB:VRxA = `00', `01', `11' LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' LSb VRxB:VRxA = `10', `11' VREF = 1.0V, Gx = `1' LSb VDD = 1.8V LSb LSb 10-bit VRxB:VRxA = `10' (codes: 25 to 1000) VDD = VREF = 5.5V VRxB:VRxA = `00', `01', `11' LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' LSb VRxB:VRxA = `10', `11' VREF = 1.0V, Gx = `1' LSb VDD = 1.8V LSb 12-bit VRxB:VRxA = `10' (codes: 100 to 4000) VDD = VREF = 5.5V VRxB:VRxA = `00', `01', `11' See Section 2.0, "Typical LSb Performance Curves" (2) See Section 2.0, "Typical LSb VRxB:VRxA = `01' VDD = 5.5V, Gx = `1' Performance Curves" (2) See Section 2.0, "Typical LSb VRxB:VRxA = `10', `11' VREF = 1.0V, Gx = `1' Performance Curves" (2) See Section 2.0, "Typical LSb VDD = 1.8V Performance Curves" (2) This parameter is ensured by characterization. Code range dependent on resolution: 8-bit, codes 6 to 250; 10-bit, codes 25 to 1000; 12-bit, codes 100 to 4000. 2015 Microchip Technology Inc. DS20005466A-page 13 MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units -3 dB Bandwidth (see B.16 "-3 dB Bandwidth") BW -- 200 -- kHz -- 100 -- kHz VOUT(MIN) -- 0.01 -- VOUT(MAX) -- -- PM -- VDD - 0.04 66 -- SR -- 0.44 -- ISC 3 9 14 mA VBG VBGTC 1.18 -- 1.22 15 1.26 -- V ppm/C 2.0 2.2 -- -- 5.5 5.5 V V VREF pin voltage stable VOUT output linear VSS VSS -- -- -- -- 1 -64 VDD - 0.04 VDD -- -- V V pF dB VRxB:VRxA = `11' (Buffered mode) VRxB:VRxA = `10' (Unbuffered mode) VRxB:VRxA = `10' (Unbuffered mode) VREF = 2.048V 0.1V VRxB:VRxA = `10', Gx = `0' Frequency = 1 kHz Output Amplifier Minimum Output Voltage Maximum Output Voltage Phase Margin Slew Rate (9) Short-Circuit Current Internal Band Gap Band Gap Voltage Band Gap Voltage Temperature Coefficient Operating Range (VDD) External Reference (VREF) VREF Input Range (1) Input Capacitance Total Harmonic Distortion (1) CREF THD Conditions VREF = 2.048V 0.1V VRxB:VRxA = `10', Gx = `0' VREF = 2.048V 0.1V VRxB:VRxA = `10', Gx = `1' 1.8V VDD 5.5V Output Amplifier's minimum drive V 1.8V VDD 5.5V Output Amplifier's maximum drive Degree CL = 400 pF RL = () V/s RL = 5 k V DAC code = Full Scale Dynamic Performance Major Code -- 45 -- nV-s 1 LSb change around major carry Transition Glitch (see 7FFh to 800h for 12-bit devices B.14 "Major-Code 1FFh to 200h for 10-bit devices Transition Glitch") 7Fh to 80h for 8-bit devices Digital Feedthrough -- <10 -- nV-s (see B.15 "Digital Feedthrough") Note 1 This parameter is ensured by design. Note 9 Within 1/2 LSb of final value when code changes from 1/4 to 3/4 of FSR. (Example: 400h to C00h in 12-bit device). DS20005466A-page 14 2015 Microchip Technology Inc. MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Parameters Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. Typ. Max. Digital Inputs/Outputs (CS, SCK, SDI, SDO, LAT0/HVC) Schmitt Trigger VIH 0.45 VDD -- -- High-Input Threshold 0.5 VDD -- -- -- -- 0.2 VDD Schmitt Trigger VIL Low-Input Threshold -- 0.1 VDD -- Hysteresis of Schmitt VHYS Trigger Inputs VSS -- 0.3 VDD Output Low Voltage VOL VSS -- 0.3 VDD Output High Voltage VOH 0.7VDD -- VDD 0.7VDD -- VDD Input Leakage Current IIL -1 -- 1 Pin Capacitance CIN, COUT -- 10 -- 2015 Microchip Technology Inc. Units V V V Conditions 2.7V VDD 5.5V 1.8V VDD 2.7V V V V V V A pF IOL = 5 mA, VDD = 5.5V IOL = 1 mA, VDD = 1.8V IOH = -2.5 mA, VDD = 5.5V IOH = -1 mA, VDD = 1.8V VIN = VDD and VIN = VSS fC = 20 MHz DS20005466A-page 15 MCP48FVBXX DC CHARACTERISTICS (CONTINUED) DC Characteristics Parameters RAM Value Value Range DAC Register POR/BOR Value PDCON Initial Factory Setting Power Requirements Power Supply Sensitivity (see B.17 "Power-Supply Sensitivity (PSS)") DS20005466A-page 16 Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +2.7V to 5.5V, VREF = +2.048V to VDD, VSS = 0V Gx = `0', RL = 5 k from VOUT to GND, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. N 0h 0h 0h N PSS -- -- -- Typ. Max. -- FFh -- 3FFh -- FFFh See Table 4-2 See Table 4-2 See Table 4-2 See Table 4-2 0.002 0.002 0.002 0.005 0.005 0.005 Units Conditions hex hex hex hex hex hex hex 8-bit 10-bit 12-bit 8-bit 10-bit 12-bit %/% %/% %/% 8-bit 10-bit 12-bit Code = 7Fh Code = 1FFh Code = 7FFh 2015 Microchip Technology Inc. MCP48FVBXX DC Notes: 1. 2. 3. 4. 5. 6. 7. This parameter is ensured by design. This parameter is ensured by characterization. POR/BOR voltage trip point is not slope dependent. Hysteresis implemented with time delay. Supply current is independent of current through the resistor ladder in mode VRxB:VRxA = `10'. The PDxB:PDxA = `01', `10', and `11' configurations should have the same current. By design, this is the worst-case current mode. Resistance is defined as the resistance between the VREF pin (mode VRxB:VRxA = `10') to VSS pin. For dual-channel devices (MCP48FVBX2), this is the effective resistance of the each resistor ladder. The resistance measurement is that of the two resistor ladders measured in parallel. 8. This gain error does not include offset error. 9. Within 1/2 LSb of final value when code changes from 1/4 to 3/4 of FSR. (Example: 400h to C00h in 12-bit device). 10. Code range dependent on resolution: 8-bit, codes 6 to 250; 10-bit, codes 25 to 1000; 12-bit, codes 100 to 4000. 11. Variation of one output voltage to mean output voltage. 2015 Microchip Technology Inc. DS20005466A-page 17 MCP48FVBXX 1.1 Reset, Power-Down, and SPI Mode Timing Waveforms and Requirements VPOR (VBOR) VDD tPORD tBORD VOUT at High Z VOUT SPI Interface is operational FIGURE 1-1: Power-on and Brown-out Reset Waveforms. 24th bit 1st bit (Write (Next command) command) 24th bit (Write command) SCK tPDE tPDD VOUT FIGURE 1-2: TABLE 1-1: SPI Power-Down Command Waveforms. RESET AND POWER-DOWN TIMING Timing Characteristics Parameters Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +1.8V to 5.5V, VSS = 0V RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Sym. Min. Typ. Max. Units Conditions tPORD -- 60 -- s Brown-out Reset Delay tBORD -- 45 -- s VDD transitions from VDD(MIN) > VPOR VOUT driven to VOUT disabled Power-Down Output Disable Time Delay TPDD -- 10.5 -- s PDxB:PDxA = `11', `10', or `01' "00" started from falling edge of the SCK at the end of the 24th clock cycle. Volatile DAC Register = FFh, VOUT = 10 mV VOUT not connected Power-Down Output Enable Time Delay TPDE -- 1 -- s PDxB:PDxA = "00" `11', `10', or `01' started from falling edge of the SCK at the end of the 24th clock cycle VOUT = VOUT - 10 mV. VOUT not connected Power-on Reset Delay DS20005466A-page 18 2015 Microchip Technology Inc. MCP48FVBXX 0.5 LSb VOUT New Value Old Value FIGURE 1-3: TABLE 1-2: VOUT Settling Time Waveform. VOUT SETTLING TIMING Timing Characteristics Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Unless otherwise noted, all parameters apply across these specified operating ranges: VDD = +1.8V to 5.5V, VSS = 0V RL = 5 k from VOUT to VSS, CL = 100 pF Typical specifications represent values for VDD = 5.5V, TA = +25C. Parameters Sym. Min. Typ. Max. Units VOUT Settling Time (0.5LSb error band, CL = 100 pF) (see B.13 "Settling Time") tS -- 7.8 -- s 8-bit Code = 40h C0h; C0h 40h (3) -- 7.8 -- s 10-bit Code = 100h 300h; 300h 100h (3) -- 7.8 -- s 12-bit Code = 400h C00h; C00h 400h (3) Note 3 Conditions Within 1/2 LSb of final value when code changes from 1/4 to 3/4 of FSR. (Example: 400h to C00h in 12-bit device). 2015 Microchip Technology Inc. DS20005466A-page 19 MCP48FVBXX HVC (1) VIHH VIH VIH VIH 98 97 CS VIL 84 96 "1" LAT VIH "1" "0" "0" 70 94 72 96 SCK 83 71 80 MSb SDO 73 SDI Note 1: LSb BIT6 - - - - - -1 74 77 MSb IN BIT6 - - - -1 LSb IN The HVC pin is for signal voltage compatibility with MCP48FEBXX devices. FIGURE 1-4: HVC (1) VIH VIH SPI Timing (Mode = 11) Waveforms. VIHH VIH 82 CS VIL 84 "1" LAT 96 94 70 96 83 71 MSb SDO 73 SDI "1" "0" "0" SCK Note 1: VIH 98 97 80 72 BIT6 - - - - - -1 LSb 74 MSb IN 77 BIT6 - - - -1 LSb IN The HVC pin is for signal voltage compatibility with MCP48FEBXX devices. FIGURE 1-5: DS20005466A-page 20 SPI Timing (Mode = 00) Waveforms. 2015 Microchip Technology Inc. MCP48FVBXX TABLE 1-3: SPI REQUIREMENTS (MODE = 11) SPI AC Characteristics Param. No. Sym. FSCK 70 71 72 Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Operating Voltage range is described in DC Characteristics. Characteristic SCK input frequency TcsA2scH CS Active (VIL) to command's 1st SCK input TscH TscL SCK input high time SCK input low time Min. Max. Units Conditions -- 10 MHz VDD = 2.7V to 5.5V (Read command) -- 20 MHz VDD = 2.7V to 5.5V (All other commands) -- 1 MHz VDD = 1.8V to 2.7V 60 -- ns 20 -- ns VDD = 2.7V to 5.5V 400 -- ns VDD = 1.8V to 2.7V 20 -- ns VDD = 2.7V to 5.5V 400 -- ns VDD = 1.8V to 2.7V 73 TdiV2scH Setup time of SDI input to SCK edge 10 -- ns 74 TscH2diL Hold time of SDI input from SCK edge 20 -- ns 77 TcsH2DOZ CS Inactive (VIH) to SDO output hi-impedance -- 50 ns Note 1 80 TscL2doV SDO data output valid after SCK edge -- 45 ns VDD = 2.7V to 5.5V -- 170 ns VDD = 1.8V to 2.7V 100 -- ns VDD = 2.7V to 5.5V s VDD = 1.8V to 2.7V 83 TscH2csL CS Inactive (VIH) after SCK edge 1 84 TcsH 94 TLATSU 50 -- ns LAT to SCK (write data 24th bit) setup time CS high time (VIH) 20 -- ns Write Data transferred (4) 96 TLAT LAT high or low time 20 -- ns 97 THVCSU HVC to SCK (1st data bit) (HVC setup time) 0 -- ns High-Voltage Commands (1) (MCP48FEBxx only) 98 THVCHD SCK (last bit of command (8th or 24th bit)) to HVC (HVC hold time) 25 -- ns High-Voltage Commands (1) (MCP48FEBxx only) Note 1 This parameter is ensured by design. Note 4 The transition of the LAT signal must occur 10 ns before the rising edge of the 24th SCK signal (Spec 94) or the current register data value may not be transferred to the output latch (VOUT) before the register is overwritten with the new value. 2015 Microchip Technology Inc. DS20005466A-page 21 MCP48FVBXX TABLE 1-4: SPI REQUIREMENTS (MODE = 00) SPI AC Characteristics Param. No. Sym. FSCK 70 71 72 Standard Operating Conditions (unless otherwise specified): Operating Temperature: -40C TA +125C (Extended) Operating Voltage range is described in DC Characteristics. Characteristic SCK input frequency TcsA2scH CS Active (VIL) to SCK input TscH TscL SCK input high time SCK input low time Min. Max. Units Conditions -- 10 MHz VDD = 2.7V to 5.5V (Read command) -- 20 MHz VDD = 2.7V to 5.5V (All other commands) -- 1 MHz VDD = 1.8V to 2.7V 60 -- ns 20 -- ns VDD = 2.7V to 5.5V 400 -- ns VDD = 1.8V to 2.7V 20 -- ns VDD = 2.7V to 5.5V 400 -- ns VDD = 1.8V to 2.7V 73 TDIV2scH Setup time of SDI input to SCK edge 10 -- ns 74 TscH2DIL Hold time of SDI input from SCK edge 20 -- ns 77 TcsH2DOZ CS Inactive (VIH) to SDO output hi-impedance -- 50 ns Note 1 80 TscL2DOV SDO data output valid after SCK edge -- 45 ns VDD = 2.7V to 5.5V -- 170 ns VDD = 1.8V to 2.7V -- 70 ns 100 -- ns VDD = 2.7V to 5.5V s VDD = 1.8V to 2.7V 82 TssL2doV SDO data output valid after CS Active (VIL) 83 TscH2csL CS Inactive (VIH) after SCK edge 1 CS high time (VIH) 50 -- ns LAT to SCK (write data 24th bit) setup time 10 -- ns LAT high or low time 50 -- ns THVCSU HVC to SCK (1st data bit) (HVC setup time) 0 -- ns High-Voltage Commands (1) (MCP48FEBXX only) THVCHD SCK (last bit of command (8th or 24th bit)) to HVC (HVC hold time) 25 -- ns High-Voltage Commands (1) (MCP48FEBXX only) 84 TcsH 94 TLATSU 96 TLAT 97 98 Write Data transferred (4) Note 1 This parameter is ensured by design. Note 4 The transition of the LAT signal must occur 10 ns before the rising edge of the 24th SCK signal (Spec 94) or the current register data value may not be transferred to the output latch (VOUT) before the register is overwritten with the new value. DS20005466A-page 22 2015 Microchip Technology Inc. MCP48FVBXX Timing Table Notes: 1. 2. 3. 4. This parameter is ensured by design. This parameter ensured by characterization. Within 1/2 LSb of final value when code changes from 1/4 to 3/4 of FSR. (Example: 400h to C00h in 12-bit device). The transition of the LAT signal must occur 10 ns before the rising edge of the 24th SCK signal (Spec 94) or the current register data value may not be transferred to the output latch (VOUT) before the register is overwritten with the new value. 2015 Microchip Technology Inc. DS20005466A-page 23 MCP48FVBXX Temperature Specifications Electrical Specifications: Unless otherwise indicated, VDD = +2.7V to +5.5V, VSS = GND. Parameters Sym. Min. Typ. Max. Units Specified Temperature Range TA -40 -- +125 C Operating Temperature Range TA -40 -- +125 C Storage Temperature Range TA -65 -- +150 C JA -- 202 -- C/W Conditions Temperature Ranges Note 1 Thermal Package Resistances Thermal Resistance, 10LD-MSOP Note 1: The MCP48FVBXX devices operate over this extended temperature range, but with reduced performance. Operation in this range must not cause TJ to exceed the Maximum Junction Temperature of +150C. DS20005466A-page 24 2015 Microchip Technology Inc. MCP48FVBXX 2.0 Note: TYPICAL PERFORMANCE CURVES The device Performance Curves are available in a separate document. This is done to keep the file size of this PDF document less than the 10 MB file attachment limit of many mail servers. The MCP48FXBXX Performance Curves document is literature number DS20005440, and can be found on the Microchip website. Look on the MCP48FVBXX product page under "Documentation and Software", in the Data Sheets category. 2015 Microchip Technology Inc. DS20005466A-page 25 MCP48FVBXX NOTES: DS20005466A-page 26 2015 Microchip Technology Inc. MCP48FVBXX 3.0 PIN DESCRIPTIONS Overviews of the pin functions are provided in Sections 3.1, "Positive Power Supply Input (VDD)" through 3.10, "SPI - Serial Clock Pin (SCK)". The descriptions of the pins for the single-DAC output device are listed in Table 3-1, and descriptions for the dual-DAC output device are listed in Table 3-2. TABLE 3-1: MCP48FVBX1 (SINGLE-DAC) PINOUT DESCRIPTION Pin MSOP-10LD Symbol I/O Buffer Type Standard Function 1 VDD -- P Supply Voltage Pin 2 CS I ST SPI Chip Select Pin 3 VREF0 A Analog Voltage Reference Input Pin 4 VOUT0 A Analog Buffered Analog Voltage Output Pin 5 NC -- -- 6 LAT0/HVC I HV ST 7 VSS -- P 8 SDO O -- SPI Serial Data Output Pin 9 SCK I ST SPI Serial Clock Pin SDI I ST SPI Serial Data Input Pin 10 Legend: TABLE 3-2: A = Analog I = Input Not Internally Connected DAC Register Latch/High-Voltage Command Pin. Latch Pin allows the value in the Serial Shift Register to transfer to the volatile DAC register. (The HVC signal is present to indicate voltage level compatibility with the nonvolatile device family (MCP48FEBXX)). Ground Reference Pin for all circuitries on the device ST = Schmitt Trigger HV = High Voltage O = Output I/O = Input/Output P = Power MCP48FVBX2 (DUAL-DAC) PINOUT DESCRIPTION Pin MSOP-10LD Symbol I/O Buffer Type 1 VDD -- P Supply Voltage Pin 2 CS I ST SPI Chip Select Pin 3 VREF A Analog Voltage Reference Input Pin (for DAC0 and DAC1) 4 VOUT0 A Analog Buffered Analog Voltage Output 0 Pin 5 VOUT1 A Analog Buffered Analog Voltage Output 1 Pin 6 LAT/HVC I HV ST DAC Register Latch/High-Voltage Command Pin. Latch Pin allows the value in the Serial Shift Register to transfer to the volatile DAC register (for DAC0 and DAC1). (The HVC signal is present to indicate voltage level compatibility with the nonvolatile device family (MCP48FEBXX)). 7 VSS -- P Ground Reference Pin for all circuitries on the device 8 SDO O -- SPI Serial Data Output Pin 9 SCK I ST SPI Serial Clock Pin SDI I ST SPI Serial Data Input Pin 10 Legend: A = Analog I = Input 2015 Microchip Technology Inc. Standard Function ST = Schmitt Trigger HV = High Voltage O = Output I/O = Input/Output P = Power DS20005466A-page 27 MCP48FVBXX 3.1 Positive Power Supply Input (VDD) 3.4 No Connect (NC) VDD is the positive supply voltage input pin. The input supply voltage is relative to VSS. The NC pin is not connected to the device. The power supply at the VDD pin should be as clean as possible for a good DAC performance. It is recommended to use an appropriate bypass capacitor of about 0.1 F (ceramic) to ground. An additional 10 F capacitor (tantalum) in parallel is also recommended to further attenuate noise present in application boards. 3.5 3.2 Voltage Reference Pin (VREF) The VREF pin is either an input or an output. When the DAC's voltage reference is configured as the VREF pin, the pin is an input. When the DAC's voltage reference is configured as the internal band gap, the pin is an output. When the DAC's voltage reference is configured as the VREF pin, there are two options for this voltage input: * VREF pin voltage buffered * VREF pin voltage unbuffered Ground (VSS) The VSS pin is the device ground reference. The user must connect the VSS pin to a ground plane through a low-impedance connection. If an analog ground path is available in the application PCB (printed circuit board), it is highly recommended that the VSS pin be tied to the analog ground path or isolated within an analog ground plane of the circuit board. 3.6 Latch Pin (LAT)/High-Voltage Command (HVC) The LAT pin is used to force the transfer of the DAC register's shift register to the DAC output register. This allows DAC outputs to be updated at the same time. The update of the VRxB:VRxA, PDxB:PDxA and Gx bits are also controlled by the LAT pin state. The pin is compatible with HVC voltage levels that are used for the nonvolatile MCP48FEBXX devices. The buffered option is offered in cases where the external reference voltage does not have sufficient current capability to not drop its voltage when connected to the internal resistor ladder circuit. 3.7 When the DAC's voltage reference is configured as the device VDD, the VREF pin is disconnected from the internal circuit. The CS pin enables/disables the serial interface. The serial interface must be enabled for the SPI commands to be received by the device. When the DAC's voltage reference is configured as the internal band gap, the VREF pin's drive capability is minimal, so the output signal should be buffered. Refer to Section 6.2, "SPI Serial Interface" for more details of SPI Serial Interface communication. See Section 5.2, "Voltage Reference Selection" and Register 4-2 for more details on the configuration bits. 3.8 3.3 Analog Output Voltage Pin (VOUT) SPI - Chip Select Pin (CS) SPI - Serial Data In Pin (SDI) The SDI pin is the serial data input pin of the SPI interface. The SDI pin is used to write the DAC registers and configuration bits. VOUT is the DAC analog voltage output pin. The DAC output has an output amplifier. The DAC output range is dependent on the selection of the voltage reference source (and potential Output Gain selection). These are: Refer to Section 6.2, "SPI Serial Interface" for more details on SPI Serial Interface communication. * Device VDD - The full-scale range of the DAC output is from VSS to approximately VDD. * VREF pin - The full-scale range of the DAC output is from VSS to G VRL, where G is the gain selection option (1x or 2x). * Internal Band Gap - The full-scale range of the DAC output is from VSS to G (2 VBG), where G is the gain selection option (1x or 2x). The SDO pin is the serial data output pin of the SPI interface. The SDO pin is used to read the DAC registers and configuration bits. In Normal mode, the DC impedance of the output pin is about 1. In Power-Down mode, the output pin is internally connected to a known pull-down resistor of 1 k, 100 k, or open. The Power-Down Selection bits settings are shown in Register 4-3 and Table 5-5. The SCK pin is the serial clock pin of the SPI interface. The MCP48FVBXX SPI Interface only accepts external serial clocks. DS20005466A-page 28 3.9 SPI - Serial Data Out Pin (SDO) Refer to Section 6.2, "SPI Serial Interface" for more details on SPI Serial Interface communication. 3.10 SPI - Serial Clock Pin (SCK) Refer to Section 6.2, "SPI Serial Interface" for more details on SPI Serial Interface communication. 2015 Microchip Technology Inc. MCP48FVBXX 4.0 GENERAL DESCRIPTION The MCP48FVBX1 (MCP48FVB01, MCP48FVB11, and MCP48FVB21) devices are single-channel voltage output devices. The MCP48FVBX2 (MCP48FVB02, MCP48FVB12, and MCP48FVB22) devices are dual-channel voltage output devices. These devices are offered with 8-bit (MCP48FVB0X), 10-bit (MCP48FVB1X) and 12-bit (MCP48FVB2X) resolution and include volatile memory, an SPI serial interface and a write latch (LAT) pin to control the update of the written DAC value to the DAC output pin. The devices use a resistor ladder architecture. The resistor ladder DAC is driven from a software-selectable voltage reference source. The source can be either the device's internal VDD, an external VREF pin voltage (buffered or unbuffered) or an internal band gap voltage source. The DAC output is buffered with a low-power, precision output amplifier (op amp). This output amplifier provides a rail-to-rail output with low offset voltage and low noise. The gain (1x or 2x) of the output buffer is software configurable. 4.1 Power-on Reset/Brown-out Reset (POR/BOR) The internal Power-on Reset (POR)/Brown-out Reset (BOR) circuit monitors the power supply voltage (VDD) during operation. This circuit ensures correct device start-up at system power-up and power-down events. The device's RAM retention voltage (VRAM) is lower than the POR/BOR voltage trip point (VPOR/VBOR). The maximum VPOR/VBOR voltage is less than 1.8V. POR occurs as the voltage is rising (typically from 0V), while BOR occurs as the voltage is falling (typically from VDD(MIN) or higher). The POR and BOR trip points are at the same voltage, and the condition is determined by whether the VDD voltage is rising or falling (see Figure 4-1). What occurs is different depending on whether the reset is a POR or a BOR. the electrical When VPOR/VBOR < VDD < 2.7V, performance may not meet the data sheet specifications. In this region, the device is capable of reading and writing to its volatile memory if the proper serial command is executed. The devices operate from a single supply voltage. This voltage is specified from 2.7V to 5.5V for full specified operation, and from 1.8V to 5.5V for digital operation. The devices operate between 1.8V and 2.7V, but some device parameters are not specified. The main functional blocks are: * * * * * * Power-on Reset/Brown-out Reset (POR/BOR) Device Memory Resistor Ladder Output Buffer/VOUT Operation Internal Band Gap (as a voltage reference) SPI Serial Interface Module 2015 Microchip Technology Inc. DS20005466A-page 29 MCP48FVBXX 4.1.1 POWER-ON RESET 4.1.2 The Power-on Reset is the case where the device VDD is having power applied to it from the VSS voltage level. As the device powers up, the VOUT pin will float to an unknown value. When the device's VDD is above the transistor threshold voltage of the device, the output will start being pulled low. After the VDD is above the POR/BOR trip point (VBOR/VPOR), the resistor network's wiper will be loaded with the POR value (mid-scale). The volatile memory determines the analog output (VOUT) pin voltage. After the device is powered-up, the user can update the device memory. When the rising VDD voltage crosses the VPOR trip point (a Power-on Reset event), the following occurs: * The default DAC register value is latched into volatile DAC register * The default configuration bit values are latched into volatile configuration bits * POR Status bit is set (`1') * The Reset Delay Timer (tPORD) starts; when the reset delay timer (tPORD) times out, the SPI serial interface is operational. During this delay time, the SPI interface will not accept commands. * The Device Memory Address pointer is forced to 00h. BROWN-OUT RESET The Brown-out Reset occurs when a device had power applied to it and that power (voltage) drops below the specified range. When the falling VDD voltage crosses the VPOR trip point (BOR event), the following occurs: * Serial Interface is disabled * Device is forced into a Power-Down state (PDxB:PDxA = `11'). Analog circuitry is turned off * Volatile DAC Register is forced to 000h * Volatile configuration bits VRxB:VRxA and Gx are forced to `0' If the VDD voltage decreases below the VRAM voltage, all volatile memory may become corrupted. As the voltage recovers above the VPOR/VBOR voltage, see Section 4.1.1, "Power-on Reset". Serial commands not completed due to a brown-out condition may cause the memory location to become corrupted. Figure 4-1 illustrates the conditions for power-up and power-down events under typical conditions. The analog output (VOUT) state will be determined by the state of the volatile configuration bits and the DAC register. Figure 4-1 illustrates the conditions for power-up and power-down events under typical conditions. Volatile memory POR starts Reset Delay Timer. retains data value When timer times out, SPI interface can operate (if VDD VDD(MIN)) Volatile memory becomes corrupted VDD(MIN) TPORD (50 s max.) VPOR VBOR VRAM Normal Operation Device in unknown state Device in POR state POR reset forced active FIGURE 4-1: DS20005466A-page 30 Default device configuration latched into volatile configuration bits and DAC register. POR status bit is set. Below minimum operating voltage Device Device in in power unknown -down state state BOR reset, volatile DAC Register = 000h volatile VRxB:VRxA = 00 volatile Gx = 0 volatile PDxB:PDxA = 11 Power-on Reset Operation. 2015 Microchip Technology Inc. MCP48FVBXX 4.2 Device Memory User memory includes two types of memory: * Volatile Register Memory (RAM) * Device Configuration Memory Each memory address is 16 bits wide.The memory mapped register space is shown in Table 4-1. (see Section 4.2.2, "Device Configuration Memory"). 4.2.1 VOLATILE REGISTER MEMORY (RAM) There are up to five volatile memory locations: * * * * DAC0 and DAC1 Output Value Registers VREF Select Register Power-Down Configuration Register Gain and Status Register The volatile memory starts functioning when the device VDD is at (or above) the RAM retention voltage (VRAM). The volatile memory will be loaded with the default device values when the VDD rises across the VPOR/VBOR voltage trip point. Function Address MEMORY MAP (X16) Address TABLE 4-1: Function 00h Volatile DAC0 Register 10h Reserved (1, 2) 01h Volatile DAC1 Register 11h Reserved (1, 2) 02h Reserved (1) 12h Reserved (1, 2) 03h Reserved (1) 13h Reserved (1, 2) 04h Reserved (1) 14h Reserved (1, 2) 05h Reserved (1) 15h Reserved (1, 2) 06h Reserved (1) 16h Reserved (1, 2) 07h Reserved (1) 17h Reserved (1, 2) 08h VREF Register 18h Reserved (1, 2) 09h Power-Down Register 19h Reserved (1, 2) 0Ah Gain and Status Register 1Ah Reserved (1, 2) 0Bh Reserved (1) 1Bh Reserved (1, 2) 0Ch Reserved (1) 1Ch Reserved (1, 2) 0Dh Reserved (1) 1Dh Reserved (1, 2) 0Eh Reserved (1) 1Eh Reserved (1, 2) 0Fh Reserved (1) 1Fh Reserved (1, 2) Volatile Memory address range Note 1: 2: Nonvolatile Memory address range Reading a reserved memory location will result in the SPI command Command Error condition. The SDO pin will output all `0's. Forcing the CS pin to the VIH state will reset the SPI interface. Nonvolatile memory address range is shown to reflect memory map compatibility with the MCP48FEBXX family of devices. 2015 Microchip Technology Inc. DS20005466A-page 31 MCP48FVBXX 4.2.2 DEVICE CONFIGURATION MEMORY 4.2.4 The STATUS register is described in Register 4-4. 4.2.3 UNIMPLEMENTED REGISTER BITS Read commands of a valid location will read unimplemented bits as `0'. UNIMPLEMENTED (RESERVED) LOCATIONS Normal (voltage) commands (read or write) to any unimplemented memory address (reserved) will result in a command error condition (CMDERR). Read commands of a reserved location will read bits as `1'. 4.2.4.1 Default Factory POR Memory State Table 4-2 shows the default factory POR initialization of the device memory map for the 8-, 10- and 12-bit devices. FACTORY DEFAULT POR / BOR VALUES Address POR/BOR Value POR/BOR Value 10-bit 12-bit 8-bit 10-bit 12-bit Function 8-bit Function Address TABLE 4-2: 00h Volatile DAC0 Register 7Fh 1FFh 7FFh 10h Reserved (1, 2) FFh 3FFh FFFh 01h Volatile DAC1 Register 7Fh 1FFh 7FFh 11h Reserved (1, 2) FFh 3FFh FFFh 02h Reserved (1) FFh 3FFh FFFh 12h Reserved (1, 2) FFh 3FFh FFFh 03h Reserved (1) FFh 3FFh FFFh 13h Reserved (1, 2) FFh 3FFh FFFh 04h Reserved (1) FFh 3FFh FFFh 14h Reserved (1, 2) FFh 3FFh FFFh 05h Reserved (1) FFh 3FFh FFFh 15h Reserved (1, 2) FFh 3FFh FFFh 06h Reserved (1) FFh 3FFh FFFh 16h Reserved (1, 2) FFh 3FFh FFFh 07h Reserved (1) FFh 3FFh FFFh 17h Reserved (1, 2) FFh 3FFh FFFh 08h VREF Register 0000h 0000h 0000h 18h Reserved (1, 2) FFh 3FFh FFFh 09h Power-Down Register 0000h 0000h 0000h 19h Reserved (1, 2) FFh 3FFh FFFh 0Ah Gain and Status Register 0080h 0080h 0080h 1Ah Reserved (1, 2) FFh 3FFh FFFh 0Bh Reserved (1) FFh 3FFh FFFh 1Bh Reserved (1, 2) FFh 3FFh FFFh 0Ch Reserved (1) FFh 3FFh FFFh 1Ch Reserved (1, 2) FFh 3FFh FFFh 0Dh Reserved (1) FFh 3FFh FFFh 1Dh Reserved (1, 2) FFh 3FFh FFFh 0Eh Reserved (1) FFh 3FFh FFFh 1Eh Reserved (1, 2) FFh 3FFh FFFh 0Fh FFh 3FFh FFFh 1Fh FFh 3FFh FFFh Reserved (1) Volatile Memory address range Note 1: 2: Reserved (1, 2) Nonvolatile Memory address range Reading a reserved memory location will result in the SPI command Command Error condition. The SDO pin will output all `0's. Forcing the CS pin to the VIH state will reset the SPI interface. Nonvolatile memory address range is shown to reflect memory map compatibility with the MCP48FEBXX family of devices. DS20005466A-page 32 2015 Microchip Technology Inc. MCP48FVBXX 4.2.5 DEVICE REGISTERS Register 4-1 shows the format of the DAC Output Value registers. These registers will be either 8 bits, 10 bits, or 12 bits wide. The values are right justified. REGISTER 4-1: DAC0 AND DAC1 REGISTERS U-0 U-0 U-0 U-0 12-bit -- -- -- -- D11 D10 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00 10-bit -- -- -- -- --(1) --(1) D09 D08 D07 D06 D05 D04 D03 D02 D01 D00 8-bit -- -- -- -- --(1) --(1) --(1) --(1) D07 D06 D05 D04 D03 D02 D01 D00 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 bit 15 bit 0 Legend: R = Readable bit -n = Value at POR = 12-bit device 12-bit 10-bit W = Writable bit `1' = Bit is set = 10-bit device U = Unimplemented bit, read as `0' `0' = Bit is cleared = 8-bit device x = Bit is unknown 8-bit bit 15-12 bit 15-10 bit 15-8 Unimplemented: Read as `0' bit 11-0 -- -- D11-D00: DAC Output value - 12-bit devices FFFh =Full-Scale output value 7FFh =Mid-Scale output value 000h =Zero-Scale output value -- bit 9-0 -- D09-D00: DAC Output value - 10-bit devices 3FFh =Full-Scale output value 1FFh =Mid-Scale output value 000h =Zero-Scale output value -- -- bit 7-0 D07-D00: DAC Output value - 8-bit devices FFh =Full-Scale output value 7Fh =Mid-Scale output value 000h =Zero-Scale output value Note 1: Unimplemented bit, read as `0'. 2015 Microchip Technology Inc. DS20005466A-page 33 MCP48FVBXX Register 4-2 shows the format of the Voltage Reference Control Register. Each DAC has two bits to control the source of the voltage reference of the DAC. REGISTER 4-2: Single Dual VOLTAGE REFERENCE (VREF) CONTROL REGISTER (ADDRESS 08h) U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- R/W-0 R/W-0 R/W-0 R/W-0 --(1) --(1) VR0B VR0A VR1B VR1A VR0B VR0A bit 15 bit 0 Legend: R = Readable bit W = Writable bit -n = Value at POR `1' = Bit is set = Single-channel device U = Unimplemented bit, read as `0' `0' = Bit is cleared = Dual-channel device Single Dual bit 15-2 bit 15-4 Unimplemented: Read as `0' bit 1-0 bit 3-0 VRxB-VRxA: DAC Voltage Reference Control bits 11 =VREF pin (Buffered); VREF buffer enabled 10 =VREF pin (Unbuffered); VREF buffer disabled 01 =Internal Band Gap (1.22V typical); VREF buffer enabled VREF voltage driven when powered-down 00 =VDD (Unbuffered); VREF buffer disabled. Use this state with Power-Down bits for lowest current. Note 1: Unimplemented bit, read as `0'. DS20005466A-page 34 x = Bit is unknown 2015 Microchip Technology Inc. MCP48FVBXX Register 4-3 shows the format of the Power-Down Control Register. Each DAC has two bits to control the Power-Down state of the DAC. REGISTER 4-3: Single Dual POWER-DOWN CONTROL REGISTER (ADDRESS 09h) U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- R/W-0 R/W-0 R/W-0 R/W-0 --(1) --(1) PD0B PD0A PD1B PD1A PD0B PD0A bit 15 bit 0 Legend: R = Readable bit W = Writable bit -n = Value at POR `1' = Bit is set = Single-channel device U = Unimplemented bit, read as `0' `0' = Bit is cleared = Dual-channel device Single Dual bit 15-2 bit 15-4 Unimplemented: Read as `0' bit 1-0 bit 3-0 PDxB-PDxA: DAC Power-Down Control bits (2) 11 =Powered Down - VOUT is open circuit. 10 =Powered Down - VOUT is loaded with a 100 k resistor to ground. 01 =Powered Down - VOUT is loaded with a 1 k resistor to ground. 00 =Normal Operation (Not powered-down) Note 1: 2: Unimplemented bit, read as `0'. See Table 5-5 and Figure 5-10 for more details. 2015 Microchip Technology Inc. x = Bit is unknown DS20005466A-page 35 MCP48FVBXX Register 4-4 shows the format of the volatile Gain Control and System Status Register. Each DAC has one bit to control the gain of the DAC and three Status bits. REGISTER 4-4: Single Dual GAIN CONTROL AND SYSTEM STATUS REGISTER (ADDRESS 0Ah) U-0 U-0 U-0 U-0 U-0 U-0 -- -- -- -- -- -- --(1) G0 -- -- -- -- -- -- G1 G0 U-0 U-0 U-0 U-0 U-0 U-0 U-0 POR -- -- -- -- -- -- -- POR -- -- -- -- -- -- R/W-0 R/W-0 R/C-1 bit 15 -- bit 0 Legend: R = Readable bit W = Writable bit -n = Value at POR `1' = Bit is set = Single-channel device C = Clearable bit `0' = Bit is cleared = Dual-channel device U = Unimplemented bit, read as `0' x = Bit is unknown Single Dual bit 15-9 bit 15-10 Unimplemented: Read as `0' -- bit 9 G1: DAC1 Output Driver Gain control bits (Dual-channel device only) 1 =2x Gain 0 =1x Gain bit 8 bit 8 G0: DAC0 Output Driver Gain control bits 1 =2x Gain 0 =1x Gain bit 7 bit 7 POR: Power-on Reset (Brown-out Reset) Status bit This bit indicates if a Power-on Reset (POR) or Brown-out Reset (BOR) event has occurred since the last read command of this register. Reading this register clears the state of the POR Status bit. 1 = A POR (BOR) event occurred since the last read of this register. Reading this register clears this bit. 0 = A POR (BOR) event has not occurred since the last read of this register. bit 6-0 bit 6-0 Unimplemented: Read as `0' Note 1: Unimplemented bit, read as `0'. DS20005466A-page 36 2015 Microchip Technology Inc. MCP48FVBXX 5.0 The functional blocks of the DAC include: DAC CIRCUITRY * * * * * * The Digital-to-Analog Converter circuitry converts a digital value into its analog representation. The description details the functional operation of the device. The DAC Circuit uses a resistor ladder implementation. Devices have up to two DACs. Figure 5-1 shows the functional block diagram for the MCP48FVBXX DAC circuitry. VDD Voltage Reference Selection Resistor Ladder Voltage Reference Selection Output Buffer/VOUT Operation Internal Band Gap (as a voltage reference) Latch Pin (LAT) Power-Down Operation Power-Down Operation PD1:PD0 and VREF1:VREF0 VREF + - VDD VDD VREF1:VREF0 PD1:PD0 and BGEN Band Gap (1.22V typical) VREF1:VREF0 PD1:PD0 VDD A (RL) RS(2n) DAC Output Selection Power-Down Operation PD1:PD0 VW RS(2n - 1) VOUT + - Output Buffer/VOUT Operation RRL RS(2n - 3) 100 k PD1:PD0 Gain (1x or 2x) RS(2n - 2) 1 k VRL Internal Band Gap Power-Down Operation (~140 k) DAC Register Value VW = ------------------------------------------------------------------------------ V RL # of Resistors in Resistor Ladder RS(2) Where: # of Resistors in Resistor Ladder = Resistor Ladder 256 (MCP48FVB0X) = 1024 (MCP48FVB1X) RS(1) = 4096 (MCP48FVB2X) B FIGURE 5-1: MCP48FVBXX DAC Module Block Diagram. 2015 Microchip Technology Inc. DS20005466A-page 37 MCP48FVBXX 5.1 Resistor Ladder PD1:PD0 The Resistor Ladder is a digital potentiometer with the B terminal internally grounded and the A terminal connected to the selected reference voltage (see Figure 5-2). The volatile DAC register controls the wiper position. The wiper voltage (VW) is proportional to the DAC register value divided by the number of resistor elements (RS) in the ladder (256, 1024 or 4096) related to the VRL voltage. The output of the resistor network will drive the input of an output buffer. VRL DAC Register RS(2n) 2n - 1 RW (1) RS(2n - 1) RRL 2n - 2 RW (1) RS(2n - 2) The Resistor Network is made up of these three parts: VW * Resistor Ladder (string of RS elements) * Wiper switches * DAC Register decode The resistor ladder (RRL) has a typical impedance of approximately 140 k. This resistor ladder resistance (RRL) may vary from device to device by up to 20%. Since this is a voltage divider configuration, the actual RRL resistance does not affect the output given a fixed voltage at VRL. Equation 5-1 shows the calculation for the step resistance: EQUATION 5-1: RS CALCULATION R RL R S = ------------ 256 Note: 8-bit device 1 RW RS(1) (1) 0 (1) RW Analog Mux DAC Register Value V W = ------------------------------------------------------------------------------ V RL # of Resistors in Resistor Ladder Where: # of Resistors in Resistor Ladder = 256 (MCP48FVB0X) = 1024 (MCP48FVB1X) = 4096 (MCP48FVB2X) R RL RS = --------------- 1024 10-bit device R RL RS = --------------- 4096 12-bit device Note 1: The analog switch resistance (RW) does not affect performance due to the voltage divider configuration. FIGURE 5-2: Block Diagram. Resistor Ladder Model The maximum wiper position is 2n - 1, while the number of resistors in the resistor ladder is 2n. This means that when the DAC register is at full-scale, there is one resistor element (RS) between the wiper and the VRL voltage. If the unbuffered VREF pin is used as the VRL voltage source, this voltage source should have a low output impedance. When the DAC is powered-down, the resistor ladder is disconnected from the selected reference voltage. DS20005466A-page 38 2015 Microchip Technology Inc. MCP48FVBXX Voltage Reference Selection The resistor ladder has up to four sources for the reference voltage. Two User Control bits (VREF1:VREF0) are used to control the selection, with the selection connected to the VRL node (see Figures 5-3 and 5-4). The four voltage source options for the Resistor Ladder are: 1. 2. 3. 4. VDD pin voltage Internal Voltage Reference (VBG) VREF pin voltage unbuffered VREF pin voltage internally buffered VREF1:VREF0 VREF VDD Band Gap Reference Selection 5.2 VRL Buffer FIGURE 5-3: Resistor Ladder Reference Voltage Selection Block Diagram. The selection of the voltage is specified with the volatile VREF1:VREF0 configuration bits (see Register 4-2). On a POR/BOR event, the default state of the configuration bits is latched into the volatile VREF1:VREF0 configuration bits. VDD PD1:PD0 and VREF1:VREF0 When the user selects the VDD as reference, the VREF pin voltage is not connected to the resistor ladder. VREF + VRL - If the VREF pin is selected, then a selection has to be made between the Buffered or Unbuffered mode. 5.2.1 UNBUFFERED MODE VDD The VREF pin voltage may be from VSS to VDD. Note 1: The voltage source should have a low output impedance. If the voltage source has a high output impedance, then the voltage on the VREF pin would be lower than expected. The resistor ladder has a typical impedance of 140 k and a typical capacitance of 29 pF. 2: If the VREF pin is tied to the VDD voltage, VDD mode (VREF1:VREF0 = `00') is recommended. 5.2.2 BUFFERED MODE The VREF pin voltage may be from 0.01V to VDD - 0.04V. The input buffer (amplifier) provides low offset voltage, low noise, and a very high input impedance, with only minor limitations on the input range and frequency response. Note 1: Any variation or noises on the reference source can directly affect the DAC output. The reference voltage needs to be as clean as possible for accurate DAC performance. 2: If the VREF pin is tied to the VDD voltage, VDD mode (VREF1:VREF0 = `00') is recommended. 2015 Microchip Technology Inc. VDD VREF1:VREF0 VREF1:VREF0 PD1:PD0 and BGEN Band Gap(1) (1.22V typical) Note 1: The Band Gap voltage (VBG) is 1.22V typical. The band gap output goes through the buffer with a 2x gain to create the VRL voltage. See Section 5.4, "Internal Band Gap" for additional information on the band gap circuit. FIGURE 5-4: Reference Voltage Selection Implementation Block Diagram. 5.2.3 BAND GAP MODE If the Internal Band Gap is selected, then the external VREF pin should not be driven and only use high-impedance loads. Decoupling capacitors are recommended for optimal operation. The band gap output is buffered, but the internal switches limit the current that the output should source to the VREF pin. The resistor ladder buffer is used to drive the Band Gap voltage for the cases of multiple DAC outputs. This ensures that the resistor ladders are always properly sourced when the band gap is selected. DS20005466A-page 39 MCP48FVBXX Output Buffer/VOUT Operation VDD The Output Driver buffers the wiper voltage (VW) of the Resistor Ladder. Note: The load resistance must be kept higher than 5 k for stable and expected analog output (to meet electrical specifications). PD1:PD0 VW VOUT + Gain Note 1: Gain options are 1x and 2x. Figure 5-5 shows the block diagram of the output driver circuit. FIGURE 5-5: The user can select the output gain of the output amplifier. The gain options are: 5.3.1 a) b) Gain of 1, with either the VDD or VREF pin used as reference voltage. Gain of 2. Power-down logic also controls the output buffer operation (see Section 5.6, "Power-Down Operation") for additional information on Power-Down. In any of the three power-down modes, the op amp is powered-down and its output becomes a high impedance to the VOUT pin. PD1:PD0 (1) 1 k The DAC output is buffered with a low-power, precision output amplifier (op amp). This amplifier provides a rail-to-rail output with low offset voltage and low noise. The amplifier's output can drive the resistive and high-capacitive loads without oscillation. The amplifier provides a maximum load current which is enough for most programmable voltage reference applications. Refer to Section 1.0, "Electrical Characteristics" for the specifications of the output amplifier. 100 k 5.3 Output Driver Block Diagram. PROGRAMMABLE GAIN The amplifier's gain is controlled by the Gain (G) configuration bit (see Register 4-4) and the VRL reference selection (see Section 5.2, "Voltage Reference Selection"). The volatile G bit value can be modified by: * POR events * BOR events * SPI write commands Table 5-1 shows the gain bit operation. TABLE 5-1: OUTPUT DRIVER GAIN Gain Bit Gain 0 1 1 2 Comment -- Limits VREF pin voltages relative to device VDD voltage. DS20005466A-page 40 2015 Microchip Technology Inc. MCP48FVBXX 5.3.2 OUTPUT VOLTAGE The volatile DAC Register values, along with the device configuration bits, control the analog VOUT voltage. The volatile DAC Register's value is unsigned binary. The formula for the output voltage is given in Equation 5-2. Table 5-3 shows examples of volatile DAC register values and the corresponding theoretical VOUT voltage for the MCP48FVBXX devices. EQUATION 5-2: CALCULATING OUTPUT VOLTAGE (VOUT) 5.3.3 STEP VOLTAGE (VS) The Step Voltage is dependent on the device resolution and the calculated output voltage range. 1 LSb is defined as the ideal voltage difference between two successive codes. The step voltage can easily be calculated by using Equation 5-3. Theoretical step voltages are shown in Table 5-2 for several VREF voltages. EQUATION 5-3: VS CALCULATION V RL DAC Register Value V OUT = ------------------------------------------------------------------------------ Gain # of Resistors in Resistor Ladder VRL VS = ------------------------------------------------------------------------------ Gain # of Resistors in Resistor Ladder Where: Where: # of Resistors in = 4096 (MCP48FVB2X) Resistor Ladder = 1024 (MCP48FVB1X) # of Resistors in = 4096 (12-bit) Resistor Ladder = 1024 (10-bit) = Note: = 256 (MCP48FVB0X) When Gain = 2 (VRL = VREF) and if VREF > VDD / 2, the VOUT voltage will be limited to VDD. So if VREF = VDD, then the VOUT voltage will not change for volatile DAC Register values mid-scale and greater, since the op amp is at full-scale output. The following events update the DAC register value and therefore the analog voltage output (VOUT): * Power-on Reset * Brown-out Reset * Write command TABLE 5-2: 256 (8-bit) THEORETICAL STEP VOLTAGE (VS) (1) VREF 5.0 2.7 1.8 1.5 1.0 1.22 mV 659 V 439 V 366 V 244 V VS 4.88 mV 2.64 mV 1.76 mV 1.46 mV 977 V 10-bit 3.91 mV 8-bit 19.5 mV 10.5 mV 7.03 mV 5.86 mV Note 1:When Gain = 1x, VFS = VRL, and VZS = 0V. The VOUT voltage will start driving to the new value after any of these events has occurred. 2015 Microchip Technology Inc. DS20005466A-page 41 12-bit MCP48FVBXX 5.3.4 OUTPUT SLEW RATE Figure 5-6 shows an example of the slew rate of the VOUT pin. The slew rate can be affected by the characteristics of the circuit connected to the VOUT pin. VOUT VOUT(B) VOUT(A) DACx = A DACx= B Time V OUT B - V OUT A Slew Rate = -------------------------------------------------T FIGURE 5-6: 5.3.4.1 VOUT Pin Slew Rate. Small Capacitive Load With a small capacitive load, the output buffer's current is not affected by the capacitive load (CL). But still, the VOUT pin's voltage is not a step transition from one output value (DAC register value) to the next output value. The change of the VOUT voltage is limited by the output buffer's characteristics, so the VOUT pin voltage will have a slope from the initial voltage to the new voltage. This slope is fixed for the output buffer, and is referred to as the buffer slew rate (SRBUF). 5.3.4.2 Large Capacitive Load With a larger capacitive load, the slew rate is determined by two factors: * The output buffer's short-circuit current (ISC) * The VOUT pin's external load IOUT cannot exceed the output buffer's short-circuit current (ISC), which fixes the output buffer slew rate (SRBUF). The voltage on the capacitive load (CL), VCL, changes at a rate proportional to IOUT, which fixes a capacitive load slew rate (SRCL). The VCL voltage slew rate is limited to the slower of the output buffer's internally set slew rate (SRBUF) and the capacitive load slew rate (SRCL). 5.3.5 DRIVING RESISTIVE AND CAPACITIVE LOADS The VOUT pin can drive up to 100 pF of capacitive load in parallel with a 5 k resistive load (to meet electrical specifications). A VOUT vs. Resistive Load characterization graph is provided in the Typical Performance Curves for this device (see MCP48FXBXX - "Typical Performance Curves" DS20005440). VOUT drops slowly as the load resistance decreases after about 3.5 k. It is recommended to use a load with RL greater than 5 k. Driving large capacitive loads can cause stability problems for voltage feedback op amps. As the load capacitance increases, the feedback loop's phase margin decreases and the closed-loop bandwidth is reduced. This produces gain peaking in the frequency response with overshoot and ringing in the step response. That is, since the VOUT pin's voltage does not quickly follow the buffer's input voltage (due to the large capacitive load), the output buffer will overshoot the desired target voltage. Once the driver detects this overshoot, it compensates by forcing it to a voltage below the target. This causes voltage ringing on the VOUT pin. When driving large capacitive loads with the output buffer, a small series resistor (RISO) at the output (see Figure 5-7) improves the output buffer's stability (feedback loop's phase margin) by making the output load resistive at higher frequencies. The bandwidth will be generally lower than the bandwidth with no capacitive load. VW Op Amp VOUT VCL RISO RL CL FIGURE 5-7: Circuit to Stabilize Output Buffer for Large Capacitive Loads (CL). The RISO resistor value for your circuit needs to be selected. The resulting frequency response peaking and step response overshoot for this RISO resistor value should be verified on the bench. Modify the RISO's resistance value until the output characteristics meet your requirements. A method to evaluate the system's performance is to inject a step voltage on the VREF pin and observe the VOUT pin's characteristics. Note: DS20005466A-page 42 Additional insight into circuit design for driving capacitive loads can be found in AN884 - "Driving Capacitive Loads With Op Amps" (DS00884). 2015 Microchip Technology Inc. MCP48FVBXX TABLE 5-3: Device DAC INPUT CODE VS. CALCULATED ANALOG OUTPUT (VOUT) (VDD = 5.0V) Volatile DAC Register Value 1111 1111 1111 LSb Equation V 5.0V 5.0V/4096 1,220.7 1x VRL (4095/4096) 1 4.998779 2.5V 2.5V/4096 610.4 1x VRL (4095/4096) 1 2.499390 VRL MCP48FVB2X (12-bit) 0011 1111 1111 5.0V 5.0V/4096 1,220.7 2.5V 2.5V/4096 610.4 MCP48FVB1X (10-bit) 11 1111 1111 01 1111 1111 00 1111 1111 00 0000 0000 MCP48FVB0X (8-bit) 1111 1111 0111 1111 0011 1111 VRL (4095/4096) 2) 4.998779 2.498779 Note 1: 2: 3: (2) 1x VRL (2047/4096) 1) 1.249390 2x (2) VRL (2047/4096) 2) 2.498779 5.0V 5.0V/4096 1,220.7 1x VRL (1023/4096) 1) 1.248779 2.5V 2.5V/4096 610.4 1x VRL (1023/4096) 1) 0.624390 VRL (1023/4096) 2) 1.248779 5.0V 5.0V/4096 1,220.7 2.5V 2.5V/4096 610.4 (2) 1x VRL * (0/4096) 1) 0 1x VRL * (0/4096) 1) 0 2x (2) VRL * (0/4096) 2) 0 5.0V 5.0V/1024 4,882.8 1x VRL (1023/1024) 1 4.995117 2.5V 2.5V/1024 2,441.4 1x VRL (1023/1024) 1 2.497559 2x (2) 5.0V 5.0V/1024 4,882.8 2.5V 2.5V/1024 2,441.4 VRL (1023/1024) 2 4.995117 1x VRL (511/1024) 1 2.495117 1x VRL (511/1024) 1 1.247559 2x (2) VRL (511/1024) 2 2.495117 5.0V 5.0V/1024 4,882.8 1x VRL (255/1024) 1 1.245117 2.5V 2.5V/1024 2,441.4 1x VRL (255/1024) 1 0.622559 2x (2) VRL (255/1024) 2 1.245117 5.0V 5.0V/1024 4,882.8 2.5V 2.5V/1024 2,441.4 1x VRL (0/1024) 1 0 1x VRL (0/1024) 1 0 2x (2) VRL (0/1024) 1 0 5.0V 5.0V/256 19,531.3 1x VRL (255/256) 1 4.980469 2.5V 2.5V/256 9,765.6 1x VRL (255/256) 1 2.490234 2x (2) VRL (255/256) 2 4.980469 1x VRL (127/256) 1 2.480469 5.0V 5.0V/256 19,531.3 2.5V 2.5V/256 9,765.6 1x VRL (127/256) 1 1.240234 2x (2) VRL (127/256) 2 2.480469 5.0V 5.0V/256 19,531.3 1x VRL (63/256) 1 1.230469 2.5V 2.5V/256 9,765.6 1x VRL (63/256) 1 0.615234 VRL (63/256) 2 1.230469 1x VRL (0/256) 1 0 1x VRL (0/256) 1 0 2x (2) VRL (0/256) 2 0 2x 0000 0000 V VRL (2047/4096) 1) 2x 0000 0000 0000 Equation 1x 2x 0111 1111 1111 VOUT (3) Gain Selection (2) (1) 5.0V 5.0V/256 19,531.3 2.5V 2.5V/256 9,765.6 (2) VRL is the resistor ladder's reference voltage. It is independent of VREF1:VREF0 selection. Gain selection of 2x (Gx = `1`) requires voltage reference source to come from VREF pin (VREF1:VREF0 = `10` or `11') and requires VREF pin voltage (or VRL) VDD/2, or from the internal band gap (VREF1:VREF0 = `01'). These theoretical calculations do not take into account the Offset, Gain and Nonlinearity errors. 2015 Microchip Technology Inc. DS20005466A-page 43 MCP48FVBXX 5.4 Internal Band Gap The internal band gap is designed to drive the Resistor Ladder Buffer. The resistance of a resistor ladder (RRL) is targeted to be 140 k (40 k), which means a minimum resistance of 100 k. The band gap selection can be used across the VDD voltages while maximizing the VOUT voltage ranges. For VDD voltages below the 2 Gain VBG voltage, the output for the upper codes will be clipped to the VDD voltage. Table 5-4 shows the maximum DAC register code given device VDD and Gain bit setting. VDD DAC Gain TABLE 5-4: 5.5 2.7 2.0 (3) VOUT USING BAND GAP Max DAC Code (1) 12-bit 10-bit 8-bit Comment 1 FFFh 3FFh FFh VOUT(max) = 2.44V (2) 2 FFFh 3FFh FFh VOUT(max) = 4.88V (2) 1 FFFh 3FFh FFh VOUT(max) = 2.44V (2) 2 8DAh 236h 8Dh ~ 0 to 55% range 1 D1Dh 347h D1h ~ 0 to 82% range 2 ( 4) 68Eh 1A3h 68h Note 1: 2: 3: 4: ~ 0 to 41% range Without the VOUT pin voltage being clipped. When VBG = 1.22V typical. Band gap performance achieves full performance starting from a VDD of 2.0V. It is recommended to use Gain = 1 setting instead. DS20005466A-page 44 2015 Microchip Technology Inc. MCP48FVBXX 5.5 Latch Pin (LAT) The Latch pin controls when the volatile DAC Register value is transferred to the DAC wiper. This is useful for applications that need to synchronize the wiper(s) updates to an external event, such as zero crossing or updates to the other wipers on the device. The LAT pin is asynchronous to the serial interface operation. Serial Shift Reg Register Address Write Command 16 Clocks Vol. DAC Register x LAT Transfer SYNC Data (internal signal) DAC wiper x When the LAT pin is high, transfers from the volatile DAC register to the DAC wiper are inhibited. The volatile DAC register value(s) can still be updated. When the LAT pin is low, the volatile DAC register value is transferred to the DAC wiper. Note: This allows both the volatile DAC0 and DAC1 registers to be updated while the LAT pin is high, and to have outputs synchronously updated as the LAT pin is driven low. Figure 5-8 shows the interaction of the LAT pin and the loading of the DAC wiper x (from the volatile DAC Register x). The transfers are level driven. If the LAT pin is held low, the corresponding DAC wiper is updated as soon as the volatile DAC Register value is updated. LAT SYNC Transfer Data Comment 1 1 0 No Transfer 1 0 0 No Transfer 0 1 1 Vol. DAC Register x DAC wiper x 0 0 0 No Transfer FIGURE 5-8: LAT and DAC Interaction. The LAT pin allows the DAC wiper to be updated to an external event as well as have multiple DAC channels/devices update at a common event. Since the DAC wiper x is updated from the Volatile DAC Register x, all DACs that are associated with a given LAT pin can be updated synchronously. If the application does not require synchronization, then this signal should be tied low. Figure 5-9 shows two cases of using the LAT pin to control when the wiper register is updated relative to the value of a sine wave signal. Case 1: Zero Crossing of sine wave to update volatile DAC0 register (using LAT pin) Case 2: Fixed Point Crossing of sine wave to update volatile DAC0 register (using LAT pin) Indicates where LAT pin pulses active (volatile DAC0 register updated). FIGURE 5-9: Example Use of LAT Pin Operation. 2015 Microchip Technology Inc. DS20005466A-page 45 MCP48FVBXX Power-Down Operation * Turn off most of the DAC module's internal circuits (output op amp, resistor ladder, et al.) * Op amp output becomes high-impedance to the VOUT pin * Disconnects resistor ladder from reference voltage (VRL) Depending on the selected power-down mode, the following will occur: * VOUT pin is switched to one of two resistive pull-downs (see Table 5-5): - 100 k (typical) - 1 k (typical) * Op amp is powered-down and the VOUT pin becomes high-impedance. There is a delay (TPDE) between the PD1:PD0 bits changing from `00' to either `01', `10' or `11' with the op amp no longer driving the VOUT output and the pull-down resistors sinking current. In any of the power-down modes where the VOUT pin is not externally connected (sinking or sourcing current), the power-down current will typically be ~650 nA for a single-DAC device. As the number of DACs increases, the device's power-down current will also increase. VDD PD1:PD0 VW VOUT + PD1:PD0 (1) Gain 100 k To allow the application to conserve power when the DAC operation is not required, three power-down modes are available. The Power-Down configuration bits (PD1:PD0) control the power-down operation (see Figure 5-10 and Table 5-5). On devices with multiple DACs, each DACs power-down mode is individually controllable. All power-down modes do the following: 1 k 5.6 Note 1: Gain options are 1x and 2x. FIGURE 5-10: VOUT Power-Down Block Diagram. TABLE 5-5: PD1 PD0 0 0 POWER-DOWN BITS AND OUTPUT RESISTIVE LOAD Function Normal operation 0 1 1 k resistor to ground 1 0 100 k resistor to ground 1 1 Open circuit Table 5-6 shows the current sources for the DAC based on the selected source of the DAC's reference voltage and if the device is in normal operating mode or one of the power-down modes. TABLE 5-6: DAC CURRENT SOURCES The Power-Down bits are modified by using a write command to the volatile Power-Down register, or a POR event which loads the default Power-Down register values to the volatile Power-Down register. PD1:0 = `00', PD1:0 `00', Device VDD VREF1:0 = VREF1:0 = Current Source 00 01 10 11 00 01 10 11 Section 7.0, "SPI Commands" describes the SPI commands. The Write Command can be used to update the volatile PD1:PD0 bits. Output Op Amp Y Y Y Y N N N N Resistor Ladder Y Y N (1) Y N N N (1) N Note: The SPI serial interface circuit is not affected by the Power-Down mode. This circuit remains active in order to receive any command that might come from the host controller device. DS20005466A-page 46 RL Op Amp N Y N Y N N N N Band Gap N Y N N N Y N N Note 1: Current is sourced from the VREF pin, not the device VDD. 2015 Microchip Technology Inc. MCP48FVBXX 5.6.1 EXITING POWER-DOWN When the device exits Power-Down mode, the following occurs: * Disabled circuits (op amp, resistor ladder, et al.) are turned on * The resistor ladder is connected to selected reference voltage (VRL) * The selected pull-down resistor is disconnected * The VOUT output is driven to the voltage represented by the volatile DAC Register's value and configuration bits The VOUT output signal will require time as these circuits are powered-up and the output voltage is driven to the specified value as determined by the volatile DAC register and configuration bits. Note: Since the op amp and resistor ladder were powered-off (0V), the op amp's input voltage (VW) can be considered 0V. There is a delay (TPDD) between the PD1:PD0 bits updating to `00' and the op amp driving the VOUT output. The op amp's settling time (from 0V) needs to be taken into account to ensure the VOUT voltage reflects the selected value. A write command forcing the PD1:PD0 bits to `00', will cause the device to exit the power-down mode. 2015 Microchip Technology Inc. 5.7 DAC Registers, Configuration Bits, and Status Bits The MCP48FVBXX devices have volatile memory. Table 4-2 shows the volatile memory and its interaction due to a POR event. In the volatile memory, there are five configuration bits, the DAC registers and two volatile status bits. The volatile DAC registers will be either 12 bits (MCP48FVB2X), 10 bits (MCP48FVB1X), or 8 bits (MCP48FVB0X) wide. When the device is first powered-up, it automatically loads the device default values to the volatile memory. The volatile memory determines the analog output (VOUT) pin voltage. After the device is powered-up, the user can update the device memory. The memory is read and written using an SPI interface. Refer to Sections 6.0, "SPI Serial Interface Module" and 7.0, "SPI Commands" for more details on reading and writing the device's memory. Register 4-4 shows the operation of the device status bits, and Table 4-2 shows the default factory value of the device configuration bits after a POR/BOR event. There is one status bit (the POR bit) which indicates if the device VDD is above or below the POR trip point. After a POR event, this bit is a `1'. Reading the Gain Control and System Status register clears this bit (`0'). DS20005466A-page 47 MCP48FVBXX NOTES: DS20005466A-page 48 2015 Microchip Technology Inc. MCP48FVBXX 6.0 SPI SERIAL INTERFACE MODULE 6.2 The MCP48FVBXX's SPI Serial Interface Module supports the SPI serial protocol specification. Figure 6-1 shows a typical SPI interface connection. SPI SERIAL INTERFACE The MCP48FVBXX devices support the SPI serial protocol. This SPI operates in slave mode (does not generate the serial clock). The SPI interface uses up to four pins. These are: The command format and waveforms for the MCP48FVBXX are defined in Section 7.0, "SPI Commands". * * * * 6.1 A typical SPI Interface is shown in Figure 6-1. In the SPI interface, the Master's Output pin is connected to the Slave's Input pin, and the Master's Input pin is connected to the Slave's Output pin. Overview This section details some of the specific characteristics of the MCP48FVBXX's Serial Interface Module. The following sections discuss some of these device-specific characteristics: * Communication Data Rates * POR/BOR * Interface Pins (CS, SCK, SDI, SDO, and LAT/HVC) CS - Chip Select SCK - Serial Clock SDI - Serial Data In SDO - Serial Data Out The MCP48FVBXX SPI module supports two (of the four) standard SPI modes. These are Mode 0,0 and 1,1. The SPI mode is determined by the state of the SCK pin (VIH or VIL) when the CS pin transitions from inactive (VIH) to active (VIL). An additional HVC pin is available for High Voltage command support (for compatibility with MCP48FEBXX devices). The HVC pin is high-voltage tolerant. 6.3 Communication Data Rates The MCP48FVBXX devices support clock rates (bit rate) of up to 20 MHz for write commands and 10 MHz for read commands. For most applications, the write time will be considered more important, since that is how the device operation is controlled. 6.4 POR/BOR On a POR/BOR event, the SPI Serial Interface Module state machine is reset, which includes that the Device's Memory Address pointer is forced to 00h. Typical SPI Interface Connections Host Controller MCP48FVBXX SDO (Master Out - Slave In (MOSI)) SDI SDI (Master In - Slave Out (MISO)) SDO SCK SCK I/O CS I/O HVC (1) Note 1: The pin is compatible with HVC levels used for non-volatile MCP48FEBXX devices. FIGURE 6-1: Typical SPI Interface Block Diagram. 2015 Microchip Technology Inc. DS20005466A-page 49 MCP48FVBXX 6.5 Interface Pins (CS, SCK, SDI, SDO, and LAT/HVC) The operation of the five interface pins is discussed in this section. These pins are: * * * * * SDI (Serial Data In) SDO (Serial Data Out) SCK (Serial Clock) CS (Chip Select) LAT/HVC (High Voltage command) SERIAL DATA IN (SDI) The Serial Data In (SDI) signal is the data signal into the device. The value on this pin is latched on the rising edge of the SCK signal. 6.5.2 SERIAL DATA OUT (SDO) The Serial Data Out (SDO) signal is the data signal out of the device. The value on this pin is driven on the falling edge of the SCK signal. Once the CS pin is forced to the active level (VIL), the SDO pin will be driven. The state of the SDO pin is determined by the serial bit's position in the command, the command selected, and if there is a command error state (CMDERR). 6.5.3 THE CS SIGNAL The Chip Select (CS) signal is used to select the device and frame a command sequence. To start a command, or sequence of commands, the CS signal must transition from the inactive state (VIH) to the active state (VIL). After the CS signal has gone active, the SDO pin is driven and the clock bit counter is reset. The serial interface works on a 24-bit boundary. The Chip Select (CS) pin frames the SPI commands. 6.5.1 6.5.4 SERIAL CLOCK (SCK) (SPI FREQUENCY OF OPERATION) Note: There is a required delay after the CS pin goes active to the 1st edge of the SCK pin. If an error condition occurs for an SPI command, then the command byte's Command Error (CMDERR) bit (on the SDO pin) will be driven low (VIL). To exit the error condition, the user must take the CS pin to the VIH level. When the CS pin returns to the inactive state (VIH), the SPI module resets (including the address pointer). While the CS pin is in the inactive state (VIH), the serial interface is ignored. This allows the Host Controller to interface to other SPI devices using the same SDI, SDO, and SCK signals. 6.5.5 THE HVC SIGNAL The HVC pin is compatible with High Voltage commands levels (used with MCP48FEBXX devices). 6.6 The SPI Modes The SPI interface is specified to operate up to 20 MHz. The actual clock rate depends on the configuration of the system and the serial command used. Table 6-1 shows the SCK frequency for different configurations. The SPI module supports two (of the four) standard SPI modes. These are Mode 0,0 and 1,1. The SPI mode is determined by the state of the SCK pin (VIH or VIL) when the CS pin transitions from inactive (VIH) to active (VIL). TABLE 6-1: 6.6.1 SCK FREQUENCY Command Memory Type Access Volatile Memory Note 1: SDI, SDO Read Write 10 MHz 20 MHz (1) Write interface speed is faster than read interface speed due to read access times. MODE 0,0 In Mode 0,0: * SCK idle state = low (VIL) * Data is clocked in on the SDI pin on the rising edge of SCK * Data is clocked out on the SDO pin on the falling edge of SCK 6.6.2 MODE 1,1 In Mode 1,1: * SCK idle state = high (VIH) * Data is clocked in on the SDI pin on the rising edge of SCK * Data is clocked out on the SDO pin on the falling edge of SCK DS20005466A-page 50 2015 Microchip Technology Inc. MCP48FVBXX 7.0 The supported commands are shown in Table 7-1. These commands allow for both single data or continuous data operation. Table 7-1 also shows the required number of bit clocks for each command's different mode of operation. SPI COMMANDS This section documents the commands that the device supports. The MCP48FVBXX's SPI command format supports 32 memory address locations and two commands. The 24-bit commands (see Figure 7-1) are used to read and write to the device registers (Read Command and Write Command). These commands contain a Command Byte and two Data Bytes. The two commands are: * Write command (C1:C0 = `00') * Read command (C1:C0 = `11') TABLE 7-1: Table 7-2 shows an overview of all the SPI commands and their interaction with other device features. SPI COMMANDS - NUMBER OF CLOCKS Command Code Operation Write Command Read Command Note 1: 2: HV Mode C1 C0 0 0 No (2) Single 0 0 No (2) Continuous 1 1 No (2) Single 1 1 No (2) Continuous # of Bit Clocks (1) Data Update Rate (8-bit/10-bit/12-bit) (Data Words/Second) @ 1 MHz @ 10 MHz @ 20 MHz 24 41,666 416,666 833,333 24 n 41,666 416,666 833,333 24 41,666 416,666 N.A. 24 n 41,666 416,666 N.A. Comments For 10 data words For 10 data words "n" indicates the number of times the command operation is to be repeated. If the state of the HVC pin is VIHH, then the command is ignored, but a Command Error condition (CMDERR) will NOT be generated. 2015 Microchip Technology Inc. DS20005466A-page 51 MCP48FVBXX 7.0.1 COMMAND BYTE TABLE 7-2: The Command Byte has three fields: the address, the command, and one data bit (see Figure 7-1). The device memory is accessed when the master sends a proper command byte to select the desired operation. The memory location getting accessed is contained in the command byte's AD4:AD0 bits. The action desired is contained in the command byte's C1:C0 bits, see Table 7-3. C1:C0 determines if the desired memory location will be read or written. COMMAND BITS OVERVIEW C1:C0 bit states Command # of Bits Normal or HV 00 Write Data 24 Bits Normal 01 Reserved -- -- 10 Reserved -- -- 11 Read Data 24 Bits Normal As the command byte is being loaded into the device (on the SDI pin), the device's SDO pin is driving. The SDO pin will output high bits for the first seven bits of that command. On the 8th bit, the SDO pin will output the CMDERR bit state (see Section 7.0.3, "Error Condition"). 7.0.2 DATA BYTES These commands concatenate the two data bytes after the command byte, for a 24-bit long command (see Figure 7-1). 24-bit Command Command Byte Data Word (2 Bytes) A A A A A C C C D D D D D D D D D D D D D D D D D D D D D 1 0 M 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 4 3 2 1 0 D 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 E R R Data Bits (8, 10, or 12 bits) Memory Address Command Bits C C 1 0 (1) 0 0 = Write Data 0 1 = Reserved 1 0 = Reserved (1) 1 1 = Read Data Command Bits Note 1: This command uses the 24-bit format. FIGURE 7-1: DS20005466A-page 52 24-bit SPI Command Format. 2015 Microchip Technology Inc. MCP48FVBXX 7.0.3 ERROR CONDITION The Command Error (CMDERR) bit indicates if the five address bits received (AD4:AD0) and the two command bits received (C1:C0) are a valid combination (see Figure 7-1). The CMDERR bit is high if the combination is valid and low if the combination is invalid. SPI commands that do not have a multiple of eight clocks are ignored. Once an error condition has occurred, any following commands are ignored. All following SDO bits will be low until the CMDERR condition is cleared by forcing the CS pin to the inactive state (VIH). 7.0.3.1 Aborting a Transmission All SPI transmissions must have the correct number of SCK pulses to be executed. The command is not executed until the complete number of clocks has been received. If the CS pin is forced to the inactive state (VIH), the serial interface is reset. Partial commands are not executed. SPI is more susceptible to noise than other bus protocols. The most likely case is that noise corrupts the value of the data being clocked into the MCP48FVBXX or the SCK pin is injected with extra clock pulses. This may cause data to be corrupted in the device, or a Command Error to occur, since the address and command bits were not a valid combination. The extra SCK pulse will also cause the SPI data (SDI) and clock (SCK) to be out of sync. Forcing the CS pin to the inactive state (VIH) resets the serial interface. The MCP48FVBXX's SPI interface will ignore activity on the SDI and SCK pins until the CS pin transition to the active state is detected (VIH to VIL). 7.0.4 CONTINUOUS COMMANDS The device supports the ability to execute commands continuously. While the CS pin is in the active state (VIL), any sequence of valid commands may be received. The following example is a valid sequence of events: 1. CS pin driven active (VIL) 2. 3. 4. Read command Write command (Volatile memory) CS pin driven inactive (VIH) Note 1:It is recommended that while the CS pin is active, only one type of command should be issued. When changing commands, it is advisable to take the CS pin inactive then force it back to the active state. 2: It is also recommended that long command strings should be broken down into shorter command strings. This reduces the probability of noise on the SCK pin, corrupting the desired SPI command string. Note 1:When data is not being received by the MCP48FVBXX, it is recommended that the CS pin be forced to the inactive level (VIH). 2: It is also recommended that long continuous command strings be broken down into single commands or shorter continuous command strings. This reduces the probability of noise on the SCK pin corrupting the desired SPI commands. 2015 Microchip Technology Inc. DS20005466A-page 53 MCP48FVBXX 7.1 7.1.2 Write Command Write commands are used to transfer data to the desired memory location (from the Host controller). A continuous write mode of operation is possible when writing to the device's volatile memory registers (see Table 7-3). Figure 7-3 shows the sequence for three continuous writes. The writes do not need to be to the same volatile memory address. Write commands can be structured as either Single or Continuous. The format of the command is shown in Figures 7-2 (Single) and 7-3 (Continuous). TABLE 7-3: A write command to a volatile memory location changes that location after a properly formatted write command has been received. VOLATILE MEMORY ADDRESSES Address Single-Channel Dual-Channel 00h Yes Yes Note 1: During device communication, if the Device Address/Command combination is invalid or an unimplemented Device Address is specified, then the MCP48FVBXX will generate a Command Error state. To reset the SPI state machine, the CS pin must transition to the inactive state (VIH). 7.1.1 CONTINUOUS WRITES TO VOLATILE MEMORY 01h No Yes 08h Yes Yes 09h Yes Yes 0Ah Yes Yes SINGLE WRITE TO VOLATILE MEMORY The write operation requires that the CS pin be in the active state (VIL). Typically, the CS pin will be in the inactive state (VIH) and is driven to the active state (VIL). The 24-bit Write command (Command Byte and Data Bytes) is then clocked in on the SCK and SDI pins. Once all 24 bits have been received, the specified volatile address is updated. A write will not occur if the Write command is not exactly 24 clock pulses. This protects against system issues corrupting the volatile memory locations. Figures 7-4 and 7-5 show the waveforms for a single write (depending on SPI mode). Address Command A SDI D 4 A D 3 A D 2 A D 1 A D 0 0 0 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 C D M 1 D 5 E R R 1 1 0 0 Data bits (8, 10, or 12 bits) D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 0 9 D 0 8 D 0 7 D 0 6 D 0 5 D 0 4 D 0 3 D 0 2 D 0 1 D 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Valid (1) 0 Invalid (2, 3) Note 1: If a valid Address/Command occurs, then the data bits are dependent on the resolution of the device. 12-bit = D11:D00, 10-bit = D09:D00, and 8-bit = D07:D00. Data is right justified for ease of Host Controller operation (i.e., no data manipulation before transmitting the desired value). 2: Unimplemented data bits (D15:D12 on 12-bit device, D15:D10 on 10-bit device, D15:D08 on 8-bit device) will be output as `1'. 3: If an Error condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR condition is cleared (the CS pin is forced to the inactive state). FIGURE 7-2: DS20005466A-page 54 Write Command - SDI and SDO States. 2015 Microchip Technology Inc. MCP48FVBXX Address Command A SDI D 4 A D 3 A D 2 A D 1 A D 0 0 0 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Address Data bits (8, 10, or 12 bits) C D M 1 D 5 E R R 1 1 0 0 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 0 9 D 0 8 D 0 7 D 0 6 D 0 5 D 0 4 D 0 3 D 0 2 D 0 1 D 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Valid (1) 0 Invalid (2, 3) Command Data bits (8, 10, or 12 bits) A SDI D 4 A D 3 A D 2 A D 1 A D 0 0 0 C D M 1 D 5 E R R D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 0 9 D 0 8 D 0 7 D 0 6 D 0 5 D 0 4 D 0 3 D 0 2 D 0 1 D 0 0 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Valid (1) 0 0 0 0 0 0 0 (4) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Invalid (2, 3) Address Command Data bits (8, 10, or 12 bits) A SDI D 4 A D 3 A D 2 A D 1 A D 0 0 0 C D M 1 D 5 E R R D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 0 9 D 0 8 D 0 7 D 0 6 D 0 5 D 0 4 D 0 3 D 0 2 D 0 1 D 0 0 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Valid (1) 0 0 0 0 0 0 0 (4) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Invalid (2, 3) Note 1: If a valid Address/Command occurs, then the data bits are dependent on the resolution of the device. 12-bit = D11:D00, 10-bit = D09:D00, and 8-bit = D07:D00. Data is right justified for ease of Host Controller operation (i.e., no data manipulation before transmitting the desired value). 2: Unimplemented data bits (D15:D12 on 12-bit device, D15:D10 on 10-bit device, D15:D08 on 8-bit device) will be output as `1'. 3: If an Error condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR condition is cleared (the CS pin is forced to the inactive state). 4: This CMDERR bit will be forced to `0', regardless if this Address+Command combination is valid. This command will not be completed and requires the CS pin to return to VIH to clear the CMDERR condition. FIGURE 7-3: Continuous Write Sequence. 2015 Microchip Technology Inc. DS20005466A-page 55 MCP48FVBXX HVC (1) VIH CS VIL SCK PIC Write to SSPBUF CMDERR bit SDO bit23 bit22 bit21 bit20 bit19 bit18 bit17 bit16 bit15 bit1 bit0 SDI AD4 AD3 AD2 AD1 AD0 bit23 bit22 bit21 bit20 bit19 D1 bit1 D0 bit0 0 0 D16 D15 bit16 bit15 Input Sample Note 1: If the state of the HVC pin is VIHH, then the command is ignored, but a Command Error condition (CMDERR) will NOT be generated. FIGURE 7-4: HVC (1) 24-Bit Write Command (C1:C0 = "00") - SPI Waveform with PIC MCU (Mode 1,1). VIH CS VIL SCK PIC Write to SSPBUF CMDERR bit SDO bit23 bit22 bit21 bit20 bit19 bit18 bit17 bit16 bit15 AD4 AD3 AD2 AD1 AD0 bit23 bit22 bit21 bit20 bit19 SDI 0 0 D16 D15 bit16 bit15 bit1 bit0 D1 bit1 D0 bit0 Input Sample Note 1: If the state of the HVC pin is VIHH, then the command is ignored, but a Command Error condition (CMDERR) will NOT be generated. FIGURE 7-5: DS20005466A-page 56 24-Bit Write Command (C1:C0 = "00") - SPI Waveform with PIC MCU (Mode 0,0). 2015 Microchip Technology Inc. MCP48FVBXX 7.2 7.2.1 Read Command LAT PIN INTERACTION During a Read command of the DACx Registers, if the LAT pin transitions from VIH to VIL, then the read data may be corrupted. This is due to the fact that the data being read is the output value and not the DAC register value. The LAT pin transition causes an update of the output value. Based on the DAC output value, the DACx register value, and the Command bit where the LAT pin transitions, the value being read could be corrupted. The Read command is a 24-bit command and is used to transfer data from the specified memory location to the Host controller. The Read command can be issued to the volatile memory locations. The format of the command as well as an example SDI and SDO data is shown in Figure 7-6. The first 7-bits of the Read command determine the address and the command. The 8th clock will output the CMDERR bit on the SDO pin. By means of the remaining 16 clocks, the device will transmit the data bits of the specified address (AD4:AD0). If LAT pin transitions occur during a read of the DACx register, it is recommended that sequential reads be performed until the two most recent read values match. Then the most recent read data is good. The Read command formats include: * Single Read * Continuous Reads 7.2.2 SINGLE READ The Read command operation requires that the CS pin be in the active state (VIL). Typically, the CS pin will be in the inactive state (VIH) and is driven to the active state (VIL). The 24-bit Read command (Command Byte and Data Byte) is then clocked in on the SCK and SDI pins. The SDO pin starts driving data on the 8th bit (CMDERR bit), and the addressed data comes out on the 9th through 24th clocks. Note 1: During device communication, if the Device Address/Command combination is invalid or an unimplemented Address is specified, then the MCP48FVBXX will command error that byte. To reset the SPI state machine, the CS pin must be driven to the VIH state. 2: If the LAT pin is High (VIH), reads of the volatile DAC Register address returns that DAC's output value, not the internal register. 3: Read commands ignore any High Voltage Command levels that are present on the HVC pin. Address Command A D 4 A D 3 A D 2 A D 1 A D 0 1 1 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 SDI C M D E R R 1 0 Data bits (8, 10, or 12 bits) X X X X X X X X X X X X X X X X 1 0 1 0 1 0 1 0 d 0 d 0 d 0 d 0 d 0 d 0 d 0 d 0 d 0 d 0 d 0 d Valid (1) 0 Invalid (2, 3) Note 1: If a valid Address/Command occurs, then the data bits are dependent on the resolution of the device. 12-bit = D11:D00, 10-bit = D09:D00, and 8-bit = D07:D00. Data is right justified for ease of Host Controller operation (i.e., no data manipulation before transmitting the desired value). 2: Unimplemented data bits (D15:D12 on 12-bit device, D15:D10 on 10-bit device, D15:D08 on 8-bit device) will be output as `1'. 3: If an Error condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR condition is cleared (the CS pin is forced to the inactive state). FIGURE 7-6: Read Command - SDI and SDO States. 2015 Microchip Technology Inc. DS20005466A-page 57 MCP48FVBXX 7.2.3 CONTINUOUS READS Figure 7-7 shows the sequence for three continuous reads. The reads do not need to be to the same memory address. Continuous-reads format allows the device's memory to be read quickly. Continuous reads are possible to all memory locations. Address Command A SDI D 4 A D 3 A D 2 A D 1 A D 0 1 1 SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Address Data bits (8, 10, or 12 bits) C M D E R R 1 0 X X X X X X X X X X X X X X X X 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Valid (1) 0 Invalid (2, 3) Command Data bits (8, 10, or 12 bits) A SDI D 4 A D 3 A D 2 A D 1 A D 0 1 1 C M D E R R X X X X X X X X X X X X X X X X SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Valid (1) 0 0 0 0 0 0 0 (4) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Invalid (2, 3) Address Command Data bits (8, 10, or 12 bits) A SDI D 4 A D 3 A D 2 A D 1 A D 0 1 1 C M D E R R X X X X X X X X X X X X X X X X SDO 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Valid (1) 0 0 0 0 0 0 0 (4) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Invalid (2, 3) Note 1: If a valid Address/Command occurs, then the data bits are dependent on the resolution of the device. 12-bit = D11:D00, 10-bit = D09:D00, and 8-bit = D07:D00. Data is right justified for ease of Host Controller operation (i.e., no data manipulation before transmitting the desired value). 2: Unimplemented data bits (D15:D12 on 12-bit device, D15:D10 on 10-bit device, D15:D08 on 8-bit device) will be output as `1'. 3: If an Error condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR condition is cleared (the CS pin is forced to the inactive state). 4: This CMDERR bit will be forced to `0', regardless if this Address+Command combination is valid. This command will not be completed and requires the CS pin to return to VIH to clear the CMDERR condition. FIGURE 7-7: DS20005466A-page 58 Continuous-Reads Sequence. 2015 Microchip Technology Inc. MCP48FVBXX HVC (1) VIH CS VIL SCK PIC Write to SSPBUF CMDERR bit SDO bit23 bit22 bit21 bit20 bit19 bit18 bit17 bit16 bit15 bit1 bit0 SDI AD4 AD3 AD2 AD1 AD0 bit23 bit22 bit21 bit20 bit19 D1 bit1 D0 bit0 1 1 D16 D15 bit16 bit15 Input Sample Note 1: If the state of the HVC pin is VIHH, then the command is ignored, but a Command Error condition (CMDERR) will NOT be generated. FIGURE 7-8: HVC (1) VIH CS 24-Bit Read Command (C1:C0 = "11") - SPI Waveform with PIC MCU (Mode 1,1). VIL SCK PIC Write to SSPBUF CMDERR bit SDO bit23 bit22 bit21 bit20 bit19 bit18 bit17 bit16 bit15 AD4 AD3 AD2 AD1 AD0 bit23 bit22 bit21 bit20 bit19 SDI 1 1 D16 D15 bit16 bit15 bit1 bit0 D1 bit1 D0 bit0 Input Sample Note 1: If the state of the HVC pin is VIHH, then the command is ignored, but a Command Error condition (CMDERR) will NOT be generated. FIGURE 7-9: 24-Bit Read Command (C1:C0 = "11") - SPI Waveform with PIC MCU (Mode 0,0). 2015 Microchip Technology Inc. DS20005466A-page 59 MCP48FVBXX NOTES: DS20005466A-page 60 2015 Microchip Technology Inc. MCP48FVBXX 8.0 TYPICAL APPLICATIONS The MCP48FVBXX devices are general purpose, single/dual-channel voltage output DACs for various applications where a precision operation with low power and volatile memory is needed. C1 C2 VREF 3 Applications generally suited for the devices are: * * * * Set Point or Offset Trimming Sensor Calibration Portable Instrumentation (Battery-Powered) Motor Control 8.1 Power Supply Considerations The power source should be as clean as possible. The power supply to the device is also used for the DAC voltage reference internally if the internal VDD is selected as the resistor ladder's reference voltage (VRxB:VRxA = `00'). Any noise induced on the VDD line can affect the DAC performance. Typical applications will require a bypass capacitor in order to filter out high-frequency noise on the VDD line. The noise can be induced onto the power supply's traces or as a result of changes on the DAC output. The bypass capacitor helps to minimize the effect of these noise sources on signal integrity. Figure 8-1 shows an example of using two bypass capacitors (a 10 F tantalum capacitor and a 0.1 F ceramic capacitor) in parallel on the VDD line. These capacitors should be placed as close to the VDD pin as possible (within 4 mm). If the application circuit has separate digital and analog power supplies, the VDD and VSS pins of the device should reside on the analog plane. VDD 1 CS 2 VDD VOUT0 Analog Output VOUT1 C3 C4 9 SCK 8 SDO 4 7 V SS 5 6 LAT/HVC To MCU MCP48FVBX2 Optional (a) Circuit when VDD is selected as reference (Note: VDD is connected to the reference circuit internally.) VDD C1 C2 VDD 1 CS 2 VREF C5 VREF 3 VOUT0 4 VOUT1 5 C6 Optional Analog Output 10 SDI 9 SCK 8 SDO To MCU 7 VSS 6 LAT/HVC MCP48FVBX2 C3 C4 Optional (b) Circuit when external reference is used. C1: 0.1 F capacitor Ceramic C2: 10 F capacitor Tantalum C3: ~ 0.1 F Optional to reduce noise in VOUT pin C4: 0.1 F capacitor Ceramic C5: 10 F capacitor Tantalum C6: 0.1 F capacitor Ceramic FIGURE 8-1: Circuit. 2015 Microchip Technology Inc. 10 SDI Bypass Filtering Example DS20005466A-page 61 MCP48FVBXX 8.2 Application Examples The MCP48FVBXX devices are rail-to-rail output DACs designed to operate with a VDD range of 2.7V to 5.5V. The internal output operational amplifier is robust enough to drive common, small-signal loads directly, thus eliminating the cost and size of external buffers for most applications. The user can use gain of 1 or 2 of the output operational amplifier by setting the Configuration register bits. Also, the user can use internal VDD as the reference or use an external reference. Various user options and easy-to-use features make the devices suitable for various modern DAC applications. Application examples include: * * * * * * * * * Decreasing Output Step Size Building a "Window" DAC Bipolar Operation Selectable Gain and Offset Bipolar Voltage Output Designing a Double-Precision DAC Building Programmable Current Source Serial Interface Communication Times Power Supply Considerations Layout Considerations 8.2.1 8.2.1.1 Decreasing Output Step Size If the application is calibrating the bias voltage of a diode or transistor, a bias voltage range of 0.8V may be desired with about 200 V resolution per step. Two common methods to achieve small step size are: * Using lower VREF pin voltage: Using an external voltage reference (VREF) is an option if the external reference is available with the desired output voltage range. However, occasionally, when using a low-voltage reference voltage, the noise floor causes a SNR error that is intolerable. * Using a voltage divider on the DAC's output: Using a voltage divider provides some advantages when external voltage reference needs to be very low or when the desired output voltage is not available. In this case, a larger value reference voltage is used while two resistors scale the output range down to the precise desired level. Figure 8-2 illustrates this concept. A bypass capacitor on the output of the voltage divider plays a critical function in attenuating the output noise of the DAC and the induced noise from the environment. VDD DC SET POINT OR CALIBRATION A common application for the devices is a digitally-controlled set point and/or calibration of variable parameters, such as sensor offset or slope. For example, the MCP48FVB2X provides 4096 output steps. If voltage reference is 4.096V (where Gx = `0'), the LSb size is 1 mV. If a smaller output step size is desired, a lower external voltage reference is needed. Optional VREF VDD RSENSE VCC+ VOUT VTRIP Comp. + C1 V - R1 MCP48FVBXX VO R2 SPI 4-wire CC FIGURE 8-2: Example Circuit Of Set-Point or Threshold Calibration. EQUATION 8-1: VOUT AND VTRIP CALCULATIONS VOUT = VREF * G * DAC Register Value 2N R2 V trip = V OUT -------------------- R 1 + R 2 DS20005466A-page 62 2015 Microchip Technology Inc. MCP48FVBXX 8.2.1.2 Building a "Window" DAC 8.3 When calibrating a set point or threshold of a sensor, typically only a small portion of the DAC output range is utilized. If the LSb size is adequate enough to meet the application's accuracy needs, the unused range is sacrificed without consequences. If greater accuracy is needed, then the output range will need to be reduced to increase the resolution around the desired threshold. If the threshold is not near VREF, 2 VREF, or VSS, then creating a "window" around the threshold has several advantages. One simple method to create this "window" is to use a voltage divider network with a pull-up and pull-down resistor. Figures 8-3 and 8-5 illustrate this concept. Bipolar Operation Bipolar operation is achievable by utilizing an external operational amplifier. This configuration is desirable due to the wide variety and availability of op amps. This allows a general purpose DAC, with its cost and availability advantages, to meet almost any desired output voltage range, power and noise performance. Figure 8-4 illustrates a simple bipolar voltage source configuration. R1 and R2 allow the gain to be selected, while R3 and R4 shift the DAC's output to a selected offset. Note that R4 can be tied to VDD instead of VSS if a higher offset is desired. Optional VREF VDD Optional VREF VDD VCC+ RSENSE VCC+ R1 MCP48FVBXX R3 VO VTRIP Comp. + C1 V - VOUT R2 SPI 4-wire VCC+ R3 MCP48FVBXX VOUT VOA+ VO C1 R4 SPI 4-wire VCC- CC R2 VIN VCC- R1 FIGURE 8-3: DAC. Single-Supply "Window" FIGURE 8-4: Digitally-Controlled Bipolar Voltage Source Example Circuit. EQUATION 8-2: VOUT AND VTRIP CALCULATIONS EQUATION 8-3: VOUT = VREF * G * DAC Register Value 2N VOUT = VREF * G * V OUT R23 + V 23 R1 V TRIP = --------------------------------------------R 1 + R23 R23 Thevenin Equivalent VOUT, VOA+, AND VO CALCULATIONS VOA+ = R2R3 = ------------------R2 + R3 VOUT 2N VOUT * R4 R3 + R4 VO = VOA+ * (1 + VCC+ R2 + V CC- R 3 V23 = -----------------------------------------------------R 2 + R3 DAC Register Value R2 R1 ) - VDD * ( R2 R1 ) R1 VTRIP R23 V23 2015 Microchip Technology Inc. DS20005466A-page 63 MCP48FVBXX 8.4 Selectable Gain and Offset Bipolar Voltage Output In some applications, precision digital control of the output range is desirable. Figure 8-5 illustrates how to use DAC devices to achieve this in a bipolar or single-supply application. This circuit is typically used for linearizing a sensor whose slope and offset varies. The equation to design a bipolar "window" DAC would be utilized if R3, R4 and R5 are populated. Bipolar DAC Example Optional VCC+ Optional VREF VDD R5 VCC+ R3 MCP48FVBXX VO SPI 4-wire VOA+ C1 R4 R2 VIN R1 Step 1: Calculate the range: +2.05V - (-2.05V) = 4.1V. C1 = 0.1 F Step 2: Calculate the resolution needed: 4.1V/1 mV = 4100 Since 212 = 4096, 12-bit resolution is desired. Step 3: The amplifier gain (R2/R1), multiplied by full-scale VOUT (4.096V), must be equal to the desired minimum output to achieve bipolar operation. Since any gain can be realized by choosing resistor values (R1 + R2), the VREF value must be selected first. If a VREF of 4.096V is used, solve for the amplifier's gain by setting the DAC to 0, knowing that the output needs to be -2.05V. FIGURE 8-5: Bipolar Voltage Source with Selectable Gain and Offset. EQUATION 8-6: VOUT, VOA+, AND VO CALCULATIONS VOUT = VREF * G * VOA+ = DAC Register Value -R2 - 2.05 --------- = ----------------R1 4.096V R3 + R4 VO = VOA+ * ( 1 + R2 1 ------ = --R1 2 EQUATION 8-7: Step 4: Next, solve for R3 and R4 by setting the DAC to 4096, knowing that the output needs to be +2.05V. Thevenin Equivalent R4 2 2.05V + 0.5 4.096V ------------------------ = ------------------------------------------------------- = -- R 3 + R4 1.5 4.096V 3 If R4 = 20 k, then R3 = 10 k R2 R1 ) - VIN * ( Offset Adjust If R1 = 20 k and R2 = 10 k, the gain will be 0.5. EQUATION 8-5: 2N VOUT * R4 + VCC- * R5 The equation can be simplified to: EQUATION 8-4: VCC- VCC- An output step size of 1 mV with an output range of 2.05V is desired for a particular application. VOUT R2 R1 ) Gain Adjust BIPOLAR "WINDOW" DAC USING R4 AND R5 V CC+ R 4 + VCC- R 5 V 45 = --------------------------------------------R4 + R5 V OUT R 45 + V 45 R3 VIN+ = --------------------------------------------R3 + R45 R 4 R5 R45 = ------------------R4 + R 5 R2 R2 V O = V IN+ 1 + ------ - V A ------ R1 R1 Offset Adjust Gain Adjust DS20005466A-page 64 2015 Microchip Technology Inc. MCP48FVBXX 8.5 Designing a Double-Precision DAC 8.6 Building Programmable Current Source Figure 8-6 shows an example design of a single-supply voltage output capable of up to 24-bit resolution. This requires two 12-bit DACs. This design is simply a voltage divider with a buffered output. Figure 8-7 shows an example of building a programmable current source using a voltage follower. The current sensor resistor is used to convert the DAC voltage output into a digitally-selectable current source. Double-Precision DAC Example The smaller RSENSE is, the less power dissipated across it. However, this also reduces the resolution that the current can be controlled. If a similar application to the one developed in Bipolar DAC Example required a resolution of 1 V instead of 1 mV and a range of 0V to 4.1V, then 12-bit resolution would not be adequate. Step 1: Calculate the resolution needed: 4.1V/1 V = 4.1 x 106. Since 222 = 4.2 x 106, 22-bit resolution is desired. Since DNL = 1.0 LSb, this design can be attempted with the 12-bit DAC. Step 2: Since DAC1's VOUT1 has a resolution of 1 mV, its output only needs to be "pulled" 1/1000 to meet the 1 V target. Dividing VOUT0 by 1000 would allow the application to compensate for DAC1's DNL error. Step 3: If R2 is 100, then R1 needs to be 100 k. Step 4: The resulting transfer function is shown in Equation 8-8. VREF VDD VOUT Load VCC+ IL MCP48FVBXX Ib VCC- SPI 4-wire IL Ib = ---- RSENSE VOUT I L = ------------------ ------------R SENSE + 1 where Common-Emitter Current Gain Optional VREF VDD (or VREF) Optional VDD MCP48FVBX2 FIGURE 8-7: Source. Digitally-Controlled Current VOUT0 (DAC0) R1 SPI 4-wire VCC+ VOUT Optional VREF VDD 0.1 F R2 VCC- MCP48FVBX2 (DAC1) VOUT1 SPI 4-wire FIGURE 8-6: Simple Double-Precision DAC using MCP48FVBX2. EQUATION 8-8: VOUT CALCULATION * R2 + VOUT1 * R1 V VOUT = OUT0 R1 + R2 Where: VOUT0 = (VREF * G * DAC0 Register Value)/4096 VOUT1 = (VREF * G * DAC1 Register Value)/4096 Gx = Selected Op Amp Gain 2015 Microchip Technology Inc. DS20005466A-page 65 MCP48FVBXX 8.7 Serial Interface Communication Times Table 8-1 shows time/frequency of the supported operations of the SPI serial interface for the different serial interface operational frequencies. This, along with the VOUT output performance (such as slew rate), would be used to determine your application's volatile DAC register update rate. TABLE 8-1: SERIAL INTERFACE TIMES / FREQUENCIES Command Code Operation Write Command Read Command Note 1: 2: Mode C 1 C 0 0 0 Single 0 0 Continuous 1 1 Single 1 1 Continuous # of Bit Clocks (1) Data Update Rate (8-bit/10-bit/12-bit) (Data Words/Second) 1 MHz 10 MHz 20 MHz (2) 24 41,666 416,666 833,333 24n 41,666 416,666 833,333 24 41,666 416,666 N.A. 24n 41,666 416,666 N.A. Comments For 10 data words For 10 data words "n" indicates the number of times the command operation is to be repeated. Write command only. DS20005466A-page 66 2015 Microchip Technology Inc. MCP48FVBXX 8.8 8.8.2 Design Considerations In the design of a system with the MCP48FVBXX devices, the following considerations should be taken into account: * Power Supply Considerations * Layout Considerations 8.8.1 LAYOUT CONSIDERATIONS Several layout considerations may be applicable to your application. These may include: * Noise * PCB Area Requirements 8.8.2.1 POWER SUPPLY CONSIDERATIONS The typical application will require a bypass capacitor in order to filter high-frequency noise which can be induced onto the power supply's traces. The bypass capacitor helps to minimize the effect of noise sources on signal integrity. Figure 8-8 illustrates an appropriate bypass strategy. In this example, the recommended bypass capacitor value is 0.1 F. This capacitor should be placed as close (within 4 mm) to the device power pin (VDD) as possible. The power source supplying these devices should be as clean as possible. If the application circuit has separate digital and analog power supplies, VDD and VSS should reside on the analog plane. VDD Noise Inductively-coupled AC transients and digital switching noise can degrade the input and output signal integrity, potentially masking the MCP48FVBXX's performance. Careful board layout minimizes these effects and increases the Signal-to-Noise Ratio (SNR). Multi-layer boards utilizing a low-inductance ground plane, isolated inputs, isolated outputs and proper decoupling are critical to achieving the performance that the silicon is capable of providing. Particularly harsh environments may require shielding of critical signals. Separate digital and analog ground planes are recommended. In this case, the VSS pin and the ground pins of the VDD capacitors should be terminated to the analog ground plane. Note: Breadboards and wire-wrapped boards are not recommended. 8.8.2.2 PCB Area Requirements In some applications, PCB area is a criteria for device selection. Table 8-2 shows the typical package dimensions and area for the 10-lead MSOP package. 0.1 F VDD PACKAGE FOOTPRINT (1) TABLE 8-2: 0.1 F VSS FIGURE 8-8: Connections. SCK CS Pins SDI SDO PIC(R) Microcontroller VOUT MCP48FVBXX VREF Package Type Package Footprint Code Dimensions (mm) Area (mm2) Length Width 10 MSOP Note 1: UN 3.00 4.90 14.70 Does not include recommended land pattern dimensions. Dimensions are typical values. VSS Typical Microcontroller 2015 Microchip Technology Inc. DS20005466A-page 67 MCP48FVBXX NOTES: DS20005466A-page 68 2015 Microchip Technology Inc. MCP48FVBXX 9.0 DEVELOPMENT SUPPORT Development support can be classified into two groups. These are: * Development Tools * Technical Documentation 9.1 Development Tools The MCP48FVBXX devices currently do not have any development tools or bond-out boards. Please visit the Device's web product page (Development Tools tab) for the development tools availability after the release of this data sheet. 9.2 Technical Documentation Several additional technical documents are available to assist you in your design and development. These technical documents include Application Notes, Technical Briefs, and Design Guides. Table 9-1 lists some of these documents. TABLE 9-1: TECHNICAL DOCUMENTATION Application Note Number Title Literature # AN1326 Using the MCP4728 12-Bit DAC for LDMOS Amplifier Bias Control Applications DS01326 -- Signal Chain Design Guide DS21825 -- Analog Solutions for Automotive Applications Design Guide DS01005 2015 Microchip Technology Inc. DS20005466A-page 69 MCP48FVBXX NOTES: DS20005466A-page 70 2015 Microchip Technology Inc. MCP48FVBXX 10.0 PACKAGING INFORMATION 10.1 Package Marking Information 10-Lead MSOP Example 48FV01 548256 Device Number Device Number Code MCP48FVB01-E/UN 48FV01 MCP48FVB02-E/UN 48FV02 MCP48FVB01T-E/UN 48FV01 MCP48FVB02T-E/UN 48FV02 MCP48FVB11-E/UN 48FV11 MCP48FVB12-E/UN 48FV12 MCP48FVB11T-E/UN 48FV11 MCP48FVB12T-E/UN 48FV12 MCP48FVB21-E/UN 48FV21 MCP48FVB22-E/UN 48FV22 MCP48FVB21T-E/UN 48FV21 MCP48FVB22T-E/UN 48FV22 Legend: XX...X Y YY WW NNN e3 * Note: Code Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code Pb-free JEDEC(R) designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package. In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. 2015 Microchip Technology Inc. DS20005466A-page 71 MCP48FVBXX UN Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20005466A-page 72 2015 Microchip Technology Inc. MCP48FVBXX UN Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 2015 Microchip Technology Inc. DS20005466A-page 73 MCP48FVBXX 10-Lead Plastic Micro Small Outline Package (UN) [MSOP] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20005466A-page 74 2015 Microchip Technology Inc. MCP48FVBXX APPENDIX A: REVISION HISTORY Revision A (December 2015) * Original release of this document. 2015 Microchip Technology Inc. DS20005466A-page 75 MCP48FVBXX B.1 TERMINOLOGY Resolution Resolution is the number of DAC output states that divide the full-scale range. For the 12-bit DAC, the resolution is 212, meaning the DAC code ranges from 0 to 4095. When there are 2N resistors in the resistor ladder and 2N tap points, the full-scale DAC register code is the resistor element (1 LSb) from the source reference voltage (VDD or VREF). Note: B.2 Least Significant Bit (LSb) This is the voltage difference between two successive codes. For a given output voltage range, it is divided by the resolution of the device (Equation B-1). The range may be VDD (or VREF) to VSS (ideal), the DAC register codes across the linear range of the output driver (Measured 1), or full-scale to zero-scale (Measured 2). EQUATION B-1: LSb VOLTAGE CALCULATION Ideal V VREF VLSb(IDEAL) = DD or 2N 2N Measured 1 V - VOUT(@100) VLSb(Measured) = OUT(@4000) (4000 - 100) Measured 2 V -V VLSb = OUT(@FS)N OUT(@ZS) 2 -1 B.3 Monotonic Operation Monotonic operation means that the device's output voltage (VOUT) increases with every 1 code step (LSb) increment (from VSS to the DAC's reference voltage (VDD or VREF)). VS64 40h VS63 3Fh Wiper Code APPENDIX B: 3Eh VS3 03h VS1 02h 01h VS0 00h VW (@ tap) n=? VW = VSn + VZS(@ Tap 0) n=0 Voltage (VW ~= VOUT) FIGURE B-1: VW (VOUT). 2N = 4096 (MCP48FXB2X) = 1024 (MCP48FXB1X) = 256 (MCP48FXB0X) DS20005466A-page 76 2015 Microchip Technology Inc. MCP48FVBXX B.4 Full-Scale Error (EFS) The Full-Scale Error (see Figure B-3) is the error on the VOUT pin relative to the expected VOUT voltage (theoretical) for the maximum device DAC register code (code FFFh for 12-bit, code 3FFh for 10-bit, and code FFh for 8-bit) (see Equation B-2). The error is dependent on the resistive load on the VOUT pin (and where that load is tied to, such as VSS or VDD). For loads (to VSS) greater than specified, the full-scale error will be greater. The error in bits is determined by the theoretical voltage step size to give an error in LSb. EQUATION B-2: EFS = Total Unadjusted Error (ET) The Total Unadjusted Error (ET) is the difference between the ideal and measured VOUT voltage. Typically, calibration of the output voltage is implemented to improve system performance. The error in bits is determined by the theoretical voltage step size to give an error in LSb. Equation B-4 shows the Total Unadjusted Error calculation. EQUATION B-4: FULL-SCALE ERROR VOUT(@FS) - VIDEAL(@FS) VLSb(IDEAL) Where: EFS is expressed in LSb. VOUT(@FS) = The VOUT voltage when the DAC register code is at full-scale. VIDEAL(@FS) = The ideal output voltage when the DAC register code is at full-scale. VLSb(IDEAL) = The theoretical voltage step size. B.5 B.6 Zero-Scale Error (EZS) ET = TOTAL UNADJUSTED ERROR CALCULATION ( VOUT_Actual(@code) - VOUT_Ideal(@Code) ) VLSb(Ideal) Where: ET is expressed in LSb. VOUT_Actual(@code) = The measured DAC output voltage at the specified code. VOUT_Ideal(@code) = The calculated DAC output voltage at the specified code. ( code * VLSb(Ideal) ) VLSb(Ideal) = VREF/# Steps 12-bit = VREF/4096 10-bit = VREF/1024 8-bit = VREF/ 256 The Zero-Scale Error (see Figure B-2) is the difference between the ideal and the measured VOUT voltage with the DAC register code equal to 000h (Equation B-3). The error is dependent on the resistive load on the VOUT pin (and where that load is tied to, such as VSS or VDD). For loads (to VDD) greater than specified, the zero-scale error will be greater. The error in bits is determined by the theoretical voltage step size to give an error in LSb. EQUATION B-3: EZS = ZERO-SCALE ERROR VOUT(@ZS) VLSb(IDEAL) Where: EZS is expressed in LSb. VOUT(@ZS) = The VOUT voltage when the DAC register code is at zero-scale. VLSb(IDEAL) = The theoretical voltage step size. 2015 Microchip Technology Inc. DS20005466A-page 77 MCP48FVBXX B.7 Offset Error (EOS) The offset error is the delta voltage of the VOUT voltage from the ideal output voltage at the specified code. This code is specified where the output amplifier is in the linear operating range; for the MCP48FVBXX we specify code 100 (decimal). Offset error does not include gain error. Figure B-2 illustrates this. This error is expressed in mV. Offset error can be negative or positive. The offset error can be calibrated by software in application circuits. B.9 Gain Error (EG) Gain error is a calculation based on the ideal slope using the voltage boundaries for the linear range of the output driver (ex code 100 and code 4000) (see Figure B-3). The gain error calculation nullifies the device's offset error. Gain error indicates how well the slope of the actual transfer function matches the slope of the ideal transfer function. Gain error is usually expressed as percent of full-scale range (% of FSR) or in LSb. FSR is the ideal full-scale voltage of the DAC (see Equation B-5). Gain Error (EG) (@ code = 4000) VREF Actual Transfer Function VOUT VOUT Actual Transfer Function Zero-Scale Error (EZS) Full-Scale Error (EFS) Ideal Transfer Function 0 Offset Error (EOS) 100 Ideal Transfer Function 4000 DAC Input Code 0 100 Ideal Transfer Function shifted by Offset Error (crosses at start of defined linear range) 4000 DAC Input Code 4095 FIGURE B-2: OFFSET ERROR AND ZERO-SCALE ERROR. FIGURE B-3: GAIN ERROR AND FULL-SCALE ERROR EXAMPLE. B.8 EQUATION B-5: Offset Error Drift (EOSD) Offset error drift is the variation in offset error due to a change in ambient temperature. Offset error drift is typically expressed in ppm/oC or V/oC. EG = EXAMPLE GAIN ERROR ( VOUT(@4000) - VOS - VOUT_Ideal(@4000) ) VFull-Scale Range * 100 Where: EG is expressed in % of full-scale range (FSR). VOUT(@4000) = The measured DAC output voltage at the specified code. VOUT_Ideal(@4000) = The calculated DAC output voltage at the specified code. ( 4000 * VLSb(Ideal) ) VOS = Measured offset voltage. VFull Scale Range = Expected full-scale output value (such as the VREF voltage). B.10 Gain-Error Drift (EGD) Gain-error drift is the variation in gain error due to a change in ambient temperature. Gain error drift is typically expressed in ppm/oC (of full-scale range). DS20005466A-page 78 2015 Microchip Technology Inc. MCP48FVBXX B.11 Integral Nonlinearity (INL) The Integral Nonlinearity (INL) error is the maximum deviation of an actual transfer function from an ideal transfer function (straight line) passing through the defined end points of the DAC transfer function (after offset and gain errors have been removed). In the MCP48FVBXX, INL is calculated using the defined end points, DAC code 100 and code 4000. INL can be expressed as a percentage of full-scale range (FSR) or in LSb. INL is also called Relative Accuracy. Equation B-6 shows how to calculate the INL error in LSb and Figure B-4 shows an example of INL accuracy. Positive INL means higher VOUT voltage than ideal. Negative INL means lower VOUT voltage than ideal. EQUATION B-6: INL ERROR - VCalc_Ideal ) (V EINL = OUT VLSb(Measured) Where: EINL is expressed in LSb. VCalc_Ideal = Code * VLSb(Measured) + VOS VOUT(Code = n) = The measured DAC output voltage with a given DAC register code VLSb(Measured) = For Measured: (VOUT(4000) - VOUT(100))/3900 VOS = Measured offset voltage. B.12 Differential Nonlinearity (DNL) The Differential Nonlinearity (DNL) error (see Figure B-5) is the measure of step size between codes in actual transfer function. The ideal step size between codes is 1 LSb. A DNL error of zero would imply that every code is exactly 1 LSb wide. If the DNL error is less than 1 LSb, the DAC guarantees monotonic output and no missing codes. Equation B-7 shows how to calculate the DNL error between any two adjacent codes in LSb. EQUATION B-7: DNL ERROR ( VOUT(code = n+1) - VOUT(code = n) ) EDNL = VLSb(Measured) -1 Where: EDNL is expressed in LSb. VOUT(Code = n) = The measured DAC output voltage with a given DAC register code. VLSb(Measured) = For Measured: (VOUT(4000) - VOUT(100))/3900 7 DNL = 0.5 LSb 6 5 DNL = 2 LSb Analog 4 Output (LSb) 3 2 7 INL = < -1 LSb 6 INL = - 1 LSb 5 Analog 4 Output (LSb) 3 1 0 000 001 010 011 100 101 110 111 DAC Input Code Ideal Transfer Function INL = 0.5 LSb Actual Transfer Function 2 FIGURE B-5: DNL ACCURACY. 1 0 000 001 010 011 100 101 110 111 DAC Input Code Ideal Transfer Function Actual Transfer Function FIGURE B-4: INL ACCURACY. 2015 Microchip Technology Inc. DS20005466A-page 79 MCP48FVBXX B.13 Settling Time Settling time is the time delay required for the VOUT voltage to settle into its new output value. This time is measured from the start of code transition to when the VOUT voltage is within the specified accuracy. In the MCP48FVBXX, the settling time is a measure of the time delay until the VOUT voltage reaches within 0.5 LSb of its final value, when the volatile DAC Register changes from 1/4 to 3/4 of the full-scale range (12-bit device: 400h to C00h). B.14 Major-Code Transition Glitch Major-Code transition glitch is the impulse energy injected into the DAC analog output when the code in the DAC register changes state. It is normally specified as the area of the glitch in nV-Sec, and is measured when the digital code is changed by 1 LSb at the major carry transition. Example: 011...111 to 100...000 or 100...000 to 011...111 B.15 Digital Feedthrough Digital feedthrough is the glitch that appears at the analog output, caused by coupling from the digital input pins of the device. The area of the glitch is expressed in nV-Sec, and is measured with a full-scale change on the digital input pins. B.17 Power-Supply Sensitivity (PSS) PSS indicates how the output of the DAC is affected by changes in the supply voltage. PSS is the ratio of the change in VOUT to a change in VDD for mid-scale output of the DAC. The VOUT is measured while the VDD is varied from 5.5V to 2.7V as a step (VREF voltage held constant), and expressed in %/%, which is the % change of the DAC output voltage with respect to the % change of the VDD voltage. EQUATION B-8: PSS CALCULATION V OUT @5.5V - VOUT @2.7V ----------------------------------------------------------------------------------V OUT @5.5V PSS = ---------------------------------------------------------------------------------- 5.5V - 2.7V --------------------------------5.5V Where: PSS is expressed in %/%. VOUT(@5.5V) = The measured DAC output voltage with VDD = 5.5V. VOUT(@2.7V) = The measured DAC output voltage with VDD = 2.7V. B.18 Power-Supply Rejection Ratio (PSRR) The digital feedthrough is measured when the DAC is not being written to the output register. PSRR indicates how the output of the DAC is affected by changes in the supply voltage. PSRR is the ratio of the change in VOUT to a change in VDD for full-scale output of the DAC. The VOUT is measured while the VDD is varied 10% (VREF voltage held constant), and expressed in dB or V/V. B.16 B.19 Example: all 0s to all 1s and vice versa. -3 dB Bandwidth This is the frequency of the signal at the VREF pin that causes the voltage at the VOUT pin to fall -3 dB value from a static value on the VREF pin. The output decreases due to the RC characteristics of the resistor ladder and the characteristics of the output buffer. VOUT Temperature Coefficient The VOUT Temperature Coefficient quantifies the error in the resistor ladder's resistance ratio (DAC Register code value) and Output Buffer due to temperature drift. B.20 Absolute Temperature Coefficient The absolute temperature coefficient quantifies the error in the end-to-end output voltage (Nominal output voltage VOUT) due to temperature drift. For a DAC this error is typically not an issue due to the ratiometric aspect of the output. B.21 Noise Spectral Density Noise spectral density is a measurement of the device's internally-generated random noise, and is characterized as a spectral density (voltage per Hz). It is measured by loading the DAC to the mid-scale value and measuring the noise at the VOUT pin. It is measured in nV/Hz. DS20005466A-page 80 2015 Microchip Technology Inc. MCP48FVBXX PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. X (1) PART NO. Device X Tape and Temperature Reel Range /XX Examples: a) MCP48FVB01-E/UN: Package b) MCP48FVB01T-E/UN: Device: MCP48FVB01: Single-Channel 8-Bit Volatile DAC with External + Internal References MCP48FVB02: Dual-Channel 8-Bit Volatile DAC with External + Internal References a) MCP48FVB11-E/UN: MCP48FVB11: Single-Channel 10-Bit Volatile DAC with External + Internal References MCP48FVB12: Dual-Channel 10-Bit Volatile DAC with External + Internal References b) MCP48FVB11T-E/UN: MCP48FVB21: Single-Channel 12-Bit Volatile DAC with External + Internal References MCP48FVB22: Dual-Channel 12-Bit Volatile DAC with External + Internal References Tape and Reel: T Blank Temperature Range: E = Package: UN = = = Tape and Reel (1) Tube a) MCP48FVB21-E/UN: b) MCP48FVB21T-E/UN: -40C to +125C (Extended) a) MCP48FVB22-E/UN: Plastic Micro Small Outline (MSOP), 10-Lead b) MCP48FVB22T-E/UN: Note 2015 Microchip Technology Inc. 1: 8-bit VOUT resolution, Single channel, Tube, Extended temperature, 10-lead MSOP package 8-bit VOUT resolution, Single channel, Tape and Reel, Extended temperature, 10-lead MSOP Package 10-bit VOUT resolution, Single channel, Tube, Extended temperature, 10-lead MSOP package 10-bit VOUT resolution, Single channel, Tape and Reel, Extended temperature, 10-lead MSOP package 12-bit VOUT resolution, Single channel, Tube, Extended temperature, 10-lead MSOP package 12-bit VOUT resolution, Single channel, Tape and Reel, Extended temperature, 10-lead MSOP package 12-bit VOUT resolution, Dual channel, Tube, Extended temperature, 10-lead MSOP package 12-bit VOUT resolution, Dual channel, Tape and Reel, Extended temperature, 10-lead MSOP package Tape and Reel identifier only appears in the catalog part number description. This identifier is used for ordering purposes and is not printed on the device package. Check with your Microchip sales office for package availability for the Tape and Reel option. DS20005466A-page 81 MCP48FVBXX NOTES: DS20005466A-page 82 2015 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: * Microchip products meet the specification contained in their particular Microchip Data Sheet. * Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. * There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. * Microchip is willing to work with the customer who is concerned about the integrity of their code. * Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights unless otherwise stated. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck, MediaLB, MOST, MOST logo, MPLAB, OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC, SST, SST Logo, SuperFlash and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. The Embedded Control Solutions Company and mTouch are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet, KleerNet logo, MiWi, motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, RightTouch logo, REAL ICE, SQI, Serial Quad I/O, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries. GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other countries. All other trademarks mentioned herein are property of their respective companies. (c) 2015, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. ISBN: 978-1-5224-0047-9 QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV == ISO/TS 16949 == 2015 Microchip Technology Inc. Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. 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