19-3185; Rev 2; 8/04 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers Features Power-On Recall of Wiper Position from Nonvolatile Memory Tiny 3mm x 3mm 8-Pin TDFN Package 35ppm/C End-to-End Resistance Temperature Coefficient 5ppm/C Ratiometric Temperature Coefficient 50k/100k/200k Resistor Values Fast I2C-Compatible Serial Interface 500nA (typ) Static Supply Current Single-Supply Operation: +2.7V to +5.25V 256 Tap Positions 0.5 LSB DNL in Voltage-Divider Mode 0.5 LSB INL in Voltage-Divider Mode Functional Diagram H VDD GND 8-BIT SHIFT REGISTER 8 8-BIT 8 LATCH 256256 POSITION DECODER W L SDA SCL I2C INTERFACE A0 Applications Mechanical Potentiometer Replacement Low-Drift Programmable-Gain Amplifiers Volume Control Liquid-Crystal Display (LCD) Contrast Control POR 8-BIT NV MEMORY MAX5417 MAX5418 MAX5419 I2C is a trademark of Phillips Corp. Purchase of I2C components from Maxim Integrated Products, Inc. or one of its sublicensed Associated Companies, conveys a license under the Philips I2C Patent Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips. Ordering Information/Selector Guide TEMP RANGE I2C ADDRESS R (k) MAX5417LETA -40C to +85C 010100A0 50 8 TDFN-EP** AIB MAX5417META* -40C to +85C 010101A0 50 8 TDFN-EP** ALS PART PIN-PACKAGE TOP MARK MAX5417NETA* -40C to +85C 010110A0 50 8 TDFN-EP** ALT MAX5417PETA* MAX5418LETA -40C to +85C -40C to +85C 010111A0 010100A0 50 100 8 TDFN-EP** 8 TDFN-EP** ALU AIC MAX5418META* -40C to +85C 010101A0 100 8 TDFN-EP** ALV MAX5418NETA* -40C to +85C 010110A0 100 8 TDFN-EP** ALW MAX5418PETA* MAX5419LETA -40C to +85C -40C to +85C 010111A0 010100A0 100 200 8 TDFN-EP** 8 TDFN-EP** ALX AID MAX5419META* -40C to +85C 010101A0 200 8 TDFN-EP** ALY MAX5419NETA* -40C to +85C 010110A0 200 8 TDFN-EP** ALZ MAX5419PETA* -40C to +85C *Future product--contact factory for availability. **Exposed pad. 010111A0 200 8 TDFN-EP** AMA Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX5417/MAX5418/MAX5419 General Description The MAX5417/MAX5418/MAX5419 nonvolatile, lineartaper, digital potentiometers perform the function of a mechanical potentiometer, but replace the mechanics with a simple 2-wire digital interface, allowing communication with multiple devices. Each device performs the same function as a discrete potentiometer or variable resistor and has 256 tap points. The devices feature an internal, nonvolatile EEPROM used to store the wiper position for initialization during power-up. The fast-mode I2CTM-compatible serial interface allows communication at data rates up to 400kbps, minimizing board space and reducing interconnection complexity in many applications. Each device is available with one of four factory-preset addresses (see the Selector Guide) and features an address input for a total of eight unique address combinations. The MAX5417/MAX5418/MAX5419 provide three nominal resistance values: 50k (MAX5417), 100k (MAX5418), or 200k (MAX5419). The nominal resistor temperature coefficient is 35ppm/C end-to-end, and only 5ppm/C ratiometric. This makes the devices ideal for applications requiring a low-temperature-coefficient variable resistor, such as low-drift, programmable gainamplifier circuit configurations. The MAX5417/MAX5418/MAX5419 are available in a 3mm x 3mm 8-pin TDFN package, and are specified over the extended -40C to +85C temperature range. MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers ABSOLUTE MAXIMUM RATINGS VDD to GND ...........................................................-0.3V to +6.0V All Other Pins to GND.................................-0.3V to (VDD + 0.3V) Maximum Continuous Current into H, L, and W MAX5417......................................................................1.3mA MAX5418......................................................................0.6mA MAX5419......................................................................0.3mA Continuous Power Dissipation (TA = +70C) 8-Pin TDFN (derate 24.4mW/C above +70C) .........1951mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-60C to +150C Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at VDD = +5V, TA = +25C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (VOLTAGE-DIVIDER MODE) Resolution 256 Taps Integral Nonlinearity INL (Note 1) 0.5 LSB Differential Nonlinearity DNL (Note 1) 0.5 LSB End-to-End Temperature Coefficient TCR 35 ppm/C 5 ppm/C MAX5417_, 50 MAX5418_, 100k MAX5419_, 200k -0.6 -0.3 -0.15 LSB MAX5417_, 50k 0.6 MAX5418_, 100k MAX5419_, 200k 0.3 0.15 Ratiometric Temperature Coefficient Full-Scale Error Zero-Scale Error LSB DC PERFORMANCE (VARIABLE-RESISTOR MODE) Integral Nonlinearity (Note 2) INL VDD = 3V 3 VDD = 5V 1.5 VDD = 3V, MAX5417_, 50k, guaranteed monotonic Differential Nonlinearity (Note 2) DNL -1 LSB +2 VDD = 3V, MAX5418_, 100k 1 MAX5419_, 200k 1 VDD = 5V 1 LSB DC PERFORMANCE (RESISTOR CHARACTERISTICS) Wiper Resistance RW Wiper Capacitance CW End-to-End Resistance 2 RHL VDD = 3V to 5.25V (Note 3) 325 675 10 pF MAX5417_ 37.5 50 62.5 MAX5418_ 75 100 125 MAX5419_ 150 200 250 _______________________________________________________________________________________ k 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers (VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at VDD = +5V, TA = +25C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DIGITAL INPUTS Input High Voltage (Note 4) VIH VDD = 3.4V to 5.25V VDD < 3.4V 2.4 V 0.7 x VDD Input Low Voltage VIL VDD = 2.7V to 5.25V (Note 4) 0.8 V Low-Level Output Voltage VOL 3mA sink current 0.4 V 1 A Input Leakage Current ILEAK Input Capacitance 5 pF DYNAMIC CHARACTERISTICS MAX5417_ Wiper -3dB Bandwidth (Note 5) 100 MAX5418_ 50 MAX5419_ 25 kHz NONVOLATILE MEMORY Data Retention Endurance TA = +85C 50 TA = +25C 200,000 TA = +85C 50,000 Years Stores POWER SUPPLY Power-Supply Voltage VDD Standby Current IDD Programming Current 2.70 5.25 V Digital inputs = VDD or GND, TA = +25C 0.5 1 A During nonvolatile write; digital inputs = VDD or GND (Note 6) 200 400 A TIMING CHARACTERISTICS (VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at VDD = +5V, TA = +25C. See Figures 1 and 2.) (Note 7) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS ANALOG SECTION MAX5417_ Wiper Settling Time (Note 8) tIL 500 MAX5418_ 600 MAX5419_ 1000 ns DIGITAL SECTION SCL Clock Frequency fSCL 400 kHz Setup Time for START Condition tSU-STA 0.6 s Hold Time for START Condition tHD-STA 0.6 s CLK High Time tHIGH 0.6 s CLK Low Time tLOW 1.3 s _______________________________________________________________________________________ 3 MAX5417/MAX5418/MAX5419 ELECTRICAL CHARACTERISTICS (continued) MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers TIMING CHARACTERISTICS (continued) (VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at VDD = +5V, TA = +25C. See Figures 1 and 2.) (Note 7) PARAMETER SYMBOL CONDITIONS MIN Data Setup Time tSU-DAT 100 Data Hold Time tHD-DAT 0 TYP MAX UNITS ns 0.9 s SDA, SCL Rise Time tR 300 ns SDA, SCL Fall Time tF 300 ns Setup Time for STOP Condition tSU-STO Bus Free Time Between STOP and START Condition tBUF Minimum power-up rate = 0.2V/ms Pulse Width of Spike Suppressed tSP Maximum Capacitive Load for Each Bus Line CB (Note 9) Write NV Register Busy Time tBUSY (Note 10) 0.6 s 1.3 s 50 400 ns pF 12 ms Note 1: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VDD and L = GND. The wiper terminal is unloaded and measured with a high-input-impedance voltmeter. Note 2: The DNL and INL are measured with the potentiometer configured as a variable resistor. H is unconnected and L = GND. For the 5V condition, the wiper terminal is driven with a source current of 80A for the 50k configuration, 40A for the 100k configuration, and 20A for the 200k configuration. For the 3V condition, the wiper terminal is driven with a source current of 40A for the 50k configuration, 20A for the 100k configuration, and 10A for the 200k configuration. Note 3: The wiper resistance is measured using the source currents given in Note 2. For operation to VDD = 2.7V, see Wiper Resistance vs. Temperature in the Typical Operating Characteristics. Note 4: The device draws higher supply current when the digital inputs are driven with voltages between (VDD - 0.5V) and (GND + 0.5V). See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics. Note 5: Wiper at midscale with a 10pF load (DC measurement). L = GND; an AC source is applied to H; and the W output is measured. A 3dB bandwidth occurs when the AC W/H value is 3dB lower than the DC W/H value. Note 6: The programming current operates only during power-up and NV writes. Note 7: SCL clock period includes rise and fall times tR and tF. All digital input signals are specified with tR = tF = 2ns and timed from a voltage level of (VIL + VIH) / 2. Note 8: Wiper settling time is the worst-case 0% to 50% rise time measured between consecutive wiper positions. H = VDD, L = GND, and the wiper terminal is unloaded and measured with a 10pF oscilloscope probe (see the Typical Operating Characteristics for the tap-to-tap switching transient). Note 9: An appropriate bus pullup resistance must be selected depending on board capacitance. Refer to the document linked to this web address: www.semiconductors.philips.com/acrobat/literature/9398/39340011.pdf. Note 10: The idle time begins from the initiation of the stop pulse. 4 _______________________________________________________________________________________ 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers INL vs. TAP POSITION 0.05 0 -0.05 -0.10 0.10 0.05 0 -0.05 -0.10 -0.15 -0.15 -0.20 -0.20 -0.25 32 64 96 500 400 300 200 100 -0.25 0 128 160 192 224 256 0 32 TAP POSITION 64 96 128 160 192 224 256 0 32 64 TAP POSITION 96 128 160 192 224 256 TAP POSITION END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE WIPER TRANSIENT AT POWER-ON MAX5417 toc04 W 1V/div CL = 10pF TAP = 128 H = VDD MAX5417 toc05 1.0 END-TO-END RESISTANCE % CHANGE VDD 2V/div 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 4s/div -40 -15 10 35 85 60 TEMPERATURE (C) STANDBY SUPPLY CURRENT vs. TEMPERATURE WIPER RESISTANCE vs. TEMPERATURE 700 600 RESISTANCE () 0.8 0.6 0.4 0.2 MAX5417 toc07 1.0 MAX5417 toc06 0 VDD = 2.7V ISRC = 50A 600 RESISTANCE () RESISTANCE INL (LSB) 0.15 0.10 STANDBY SUPPLY CURRENT (A) RESISTANCE DNL (LSB) 0.15 VOLTAGE-DIVIDER MODE 0.20 700 MAX5417 toc02 MAX5417 toc01 VOLTAGE-DIVIDER MODE 0.20 WIPER RESISTANCE vs. TAP POSITION 0.25 MAX5417 toc03 DNL vs. TAP POSITION 0.25 VDD = 2.7V 500 400 VDD = 3.0V 300 VDD = 4.5V 200 VDD = 5.25V 100 0 0 -40 -15 10 35 TEMPERATURE (C) 60 85 -40 -15 10 35 60 85 TEMPERATURE (C) _______________________________________________________________________________________ 5 MAX5417/MAX5418/MAX5419 Typical Operating Characteristics (VDD = +5V, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = +5V, TA = +25C, unless otherwise noted.) INL vs. TAP POSITION (MAX5417) THD+N RESPONSE 10 400 1:1 RATIO 20Hz TO 20kHz BANDPASS THD+N (%) 1 300 0.1 200 0.01 100 0.001 VARIABLE-RESISTOR MODE VDD = 2.7V ISRC = 50A 2.5 RESISTANCE INL (LSB) 500 3.0 MAX5417 toc09 100 MAX5417 toc08 600 2.0 MAX5417 toc10 SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGE SUPPLY CURRENT (A) 1.5 1.0 0.5 0 -0.5 0.0001 0 1 2 3 5 4 -1.0 10 DIGITAL INPUT VOLTAGE (V) 100 1k 10k 100k 96 1.00 VARIABLE-RESISTOR MODE VDD = 2.7V ISRC = 10A 0.75 0.50 INL (LSB) 1.0 INL (LSB) 64 128 160 192 224 256 INL vs. TAP POSITION (MAX5419) MAX5417 toc11 VARIABLE-RESISTOR MODE VDD = 2.7V ISRC = 20A 1.5 32 TAP POSITION INL vs. TAP POSITION (MAX5418) 2.0 0 FREQUENCY (Hz) 0.5 MAX5417 toc12 0 0.25 0 -0.25 0 -0.50 -0.5 -0.75 -1.00 32 64 96 0 128 160 192 224 256 32 64 96 128 160 192 224 256 TAP POSITION TAP POSITION DNL vs. TAP POSITION (MAX5417) DNL vs. TAP POSITION (MAX5418) 0.5 VARIABLE-RESISTOR MODE 0.4 0.3 MAX5417 toc13 0 VARIABLE-RESISTOR MODE VDD = 2.7V ISRC = 20A 0.2 0.3 MAX5417 toc14 -1.0 0.1 0.2 DNL (LSB) DNL (LSB) MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers 0.1 0 0 -0.1 -0.1 -0.2 -0.2 -0.3 0 32 64 96 128 160 192 224 256 TAP POSITION 6 -0.3 0 32 64 96 128 160 192 224 256 TAP POSITION _______________________________________________________________________________________ 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers MIDSCALE WIPER RESPONSE vs. FREQUENCY (MAX5417) -5 -0.1 -0.2 CL = 10pF -10 -15 CL = 50pF -20 -25 -0.3 32 64 96 -5 CL = 10pF -10 -15 CL = 50pF -20 -30 1 128 160 192 224 256 MAX5418 TAP = 128 -25 -30 TAP POSITION 10 100 1000 1 FREQUENCY (kHz) MIDSCALE WIPER RESPONSE vs. FREQUENCY (MAX5419) 10 100 1000 FREQUENCY (kHz) TAP-TO-TAP SWITCHING TRANSIENT (MAX5417) MAX5417 toc19 0 MAX5417 toc18 0 0 WIPER RESPONSE (dB) WIPER RESPONSE (dB) 0 -5 MAX5419 TAP = 128 -10 WIPER RESPONSE (dB) DNL (LSB) 0.1 MAX5417 TAP = 128 MAX5417 toc16 VARIABLE-RESISTOR MODE VDD = 2.7V ISRC = 10A 0.2 0 MAX5417 toc15 0.3 MIDSCALE WIPER RESPONSE vs. FREQUENCY (MAX5418) MAX5417 toc17 DNL vs. TAP POSITION (MAX5419) CL = 10pF SDA 2V/div -15 -20 CL = 50pF -25 MAX5417 CL = 10pF FROM TAP 127 TO TAP 128 H = VDD -30 -35 -40 W 10mV/div -45 1 10 1000 100 1s/div FREQUENCY (kHz) TAP-TO-TAP SWITCHING TRANSIENT (MAX5418) TAP-TO-TAP SWITCHING TRANSIENT (MAX5419) MAX5417 toc20 MAX5417 toc21 SDA 2V/div SDA 2V/div W 10mV/div W 10mV/div MAX5418 CL = 10pF FROM TAP 127 TO TAP 128 H = VDD 1s/div MAX5419 CL = 10pF FROM TAP 127 TO TAP 128 H = VDD 1s/div _______________________________________________________________________________________ 7 MAX5417/MAX5418/MAX5419 Typical Operating Characteristics (continued) (VDD = +5V, TA = +25C, unless otherwise noted.) 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers MAX5417/MAX5418/MAX5419 Pin Description PIN NAME FUNCTION 1 VDD Power-Supply Input. 2.7V to 5.25V voltage range. Bypass with a 0.1F capacitor from VDD to GND. 2 SCL I2C-Interface Clock Input 3 SDA I2C-Interface Data Input 4 A0 5 GND Address Input. Sets the A0 bit in the device ID address. 6 L Low Terminal 7 W Wiper Terminal 8 H High Terminal -- EP Exposed Pad Ground tR tF SDA tSU-DAT tHD-DAT tLOW tBUF tHD-STA tSU-STA tSU-STO SCL tHIGH tHD-STA tF tR S Sr A P S PARAMETERS ARE MEASURED FROM 30% TO 70%. Figure 1. I2C Serial-Interface Timing Diagram Detailed Description VDD IOL = 3mA VOUT SDA 400pF IOH = 0mA Figure 2. Load Circuit 8 The MAX5417/MAX5418/MAX5419 contain a resistor array with 255 resistive elements. The MAX5417 has a total end-to-end resistance of 50k, the MAX5418 has an end-to-end resistance of 100k, and the MAX5419 has an end-to-end resistance of 200k. The MAX5417/MAX5418/MAX5419 allow access to the high, low, and wiper terminals for a standard voltage-divider configuration. H, L, and W can be connected in any desired configuration as long as their voltages fall between GND and VDD. A simple 2-wire I2C-compatible serial interface moves the wiper among the 256 tap points. A nonvolatile memory stores the wiper position and recalls the stored wiper position in the nonvolatile memory upon power-up. The nonvolatile memory is guaranteed for 50 years for wiper data retention and up to 200,000 wiper store cycles. _______________________________________________________________________________________ 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers Digital Interface The MAX5417/MAX5418/MAX5419 feature an internal, nonvolatile EEPROM that stores the wiper state for initialization during power-up. The shift register decodes the control and address bits, routing the data to the proper memory registers. Data can be written to a volatile memory register, immediately updating the wiper position, or data can be written to a nonvolatile register for storage. The volatile register retains data as long as the device is powered. Once power is removed, the volatile register is cleared. The nonvolatile register retains data even after power is removed. Upon power-up, the power-on reset circuitry controls the transfer of data from the nonvolatile register to the volatile register. Start and Stop Conditions Both SCL and SDA remain high when the interface is not busy. A master signals the beginning of a transmission with a START condition by transitioning SDA from high to low while SCL is high. When the master has finished communicating with the slave, it issues a STOP condition by transitioning the SDA from low to high while SCL is high. The bus is then free for another transmission (Figure 3). SDA Bit Transfer One data bit is transferred during each clock pulse. The data on the SDA line must remain stable while SCL is high (Figure 5). SCL S P START CONDITION STOP CONDITION Figure 3. Start and Stop Conditions SDA 0 1 0 1 MSB 0* 0* A0 NOP/W ACK LSB SCL *See the Ordering Information/Selector Guide section for other address options. Figure 4. Slave Address SMBus is a trademark of Intel Corporation. _______________________________________________________________________________________ 9 MAX5417/MAX5418/MAX5419 Serial Addressing The MAX5417/MAX5418/MAX5419 operate as a slave that receives data through an I2C- and SMBusTM-compatible 2-wire interface. The interface uses a serial data access (SDA) line and a serial clock line (SCL) to achieve communication between master(s) and slave(s). A master, typically a microcontroller, initiates all data transfers to the MAX5417/MAX5418/MAX5419, and generates the SCL clock that synchronizes the data transfer (Figure 1). The MAX5417/MAX5418/MAX5419 SDA line operates as both an input and an open-drain output. A pullup resistor, typically 4.7k, is required on the SDA bus. The MAX5417/MAX5418/MAX5419 SCL operates only as an input. A pullup resistor, typically 4.7k, is required on the SCL bus if there are multiple masters on the 2-wire interface, or if the master in a single-master system has an open-drain SCL output. Each transmission consists of a START (S) condition (Figure 3) sent by a master, followed by the MAX5417/MAX5418/MAX5419 7-bit slave address plus the 8th bit (Figure 4), 1 command byte (Figure 7) and 1 data byte, and finally a STOP (P) condition (Figure 3). Analog Circuitry The MAX5417/MAX5418/MAX5419 consist of a resistor array with 255 resistive elements; 256 tap points are accessible to the wiper, W, along the resistor string between H and L. The wiper tap point is selected by programming the potentiometer through the 2-wire (I2C) interface. Eight data bits, an address byte, and a control byte program the wiper position. The H and L terminals of the MAX5417/MAX5418/MAX5419 are similar to the two end terminals of a mechanical potentiometer. The MAX5417/MAX5418/MAX5419 feature power-on reset circuitry that loads the wiper position from nonvolatile memory at power-up. MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers Table 1. MAX5417/MAX5418/MAX5419 Address Codes ADDRESS BYTE PART SUFFIX A6 A5 A4 A3 A2 A1 A0 NOP/W L 0 1 0 1 0 0 0 NOP/W L 0 1 0 1 0 0 1 NOP/W M 0 1 0 1 0 1 0 NOP/W M 0 1 0 1 0 1 1 NOP/W N 0 1 0 1 1 0 0 NOP/W N 0 1 0 1 1 0 1 NOP/W P 0 1 0 1 1 1 0 NOP/W P 0 1 0 1 1 1 1 NOP/W Acknowledge The acknowledge bit is a clocked 9th bit that the recipient uses to handshake receipt of each byte of data (Figure 6). Thus, each byte transferred effectively requires 9 bits. The master generates the 9th clock pulse, and the recipient pulls down SDA during the acknowledge clock pulse, so the SDA line is stable low during the high period of the clock pulse. When the master transmits to the MAX5417/MAX5418/MAX5419, the devices generate the acknowledge bit because the MAX5417/MAX5418/ MAX5419 are the recipients. Slave Address The MAX5417/MAX5418/MAX5419 have a 7-bit-long slave address (Figure 4). The 8th bit following the 7-bit slave address is the NOP/W bit. Set the NOP/W bit low for a write command and high for a no-operation command. The MAX5417/MAX5418/MAX5419 are available in one of four possible slave addresses (Table 1). The first 4 bits (MSBs) of the MAX5417/MAX5418/MAX5419 slave addresses are always 0101. The next 2 bits are factory programmed (see Table 1). Connect the A0 input to either GND or V DD to toggle between two unique device addresses for a part. Each device must have a unique address to share the bus. Therefore, a maximum of eight MAX5417/MAX5418/MAX5419 devices can share the same bus. CLOCK PULSE FOR ACKNOWLEDGMENT START CONDITION SDA SCL 1 2 8 NOT ACKNOWLEDGE SCL SDA DATA STABLE, DATA VALID Figure 5. Bit Transfer 10 CHANGE OF DATA ALLOWED ACKNOWLEDGE Figure 6. Acknowledge ______________________________________________________________________________________ 9 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers D14 D13 D12 D11 D10 D9 MAX5417/MAX5418/MAX5419 D15 CONTROL BYTE IS STORED ON RECEIPT OF STOP CONDITION D8 ACKNOWLEDGE FROM MAX5417/MAX5418/MAX5419 S SLAVE ADDRESS 0 CONTROL BYTE A A P ACKNOWLEDGE FROM MAX5417/MAX5418/MAX5419 NOP/W Figure 7. Command Byte Received ACKNOWLEDGE FROM MAX5417/MAX5418/MAX5419 HOW CONTROL BYTE AND DATA BYTE MAP INTO MAX5417/MAX5418/MAX5419 REGISTERS D15 D14 D13 D12 D11 D10 D9 ACKNOWLEDGE FROM MAX5417/MAX5418/MAX5419 D8 D7 D6 D5 D4 D3 D2 D1 D0 ACKNOWLEDGE FROM MAX5417/MAX5418/MAX5419 S SLAVE ADDRESS 0 A CONTROL BYTE NOP/W A DATA BYTE A P 1 BYTE Figure 8. Command and Single Data Byte Received Message Format for Writing A write to the MAX5417/MAX5418/MAX5419 consists of the transmission of the device's slave address with the 8th bit set to zero, followed by at least 1 byte of information (Figure 7). The 1st byte of information is the command byte. The bytes received after the command byte are the data bytes. The 1st data byte goes into the internal register of the MAX5417/MAX5418/MAX5419 as selected by the command byte (Figure 8). Command Byte Use the command byte to select the source and destination of the wiper data (nonvolatile or volatile memory registers) and swap data between nonvolatile and volatile memory registers (see Table 2). Command Descriptions VREG: The data byte writes to the volatile memory register and the wiper position updates with the data in the volatile memory register. NVREG: The data byte writes to the nonvolatile memory register. The wiper position is unchanged. NVREGxVREG: Data transfers from the nonvolatile memory register to the volatile memory register (wiper position updates). VREGxNVREG: Data transfers from the volatile memory register into the nonvolatile memory register. ______________________________________________________________________________________ 11 MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers Table 2. Command Byte Summary ADDRESS BYTE SCL CYCLE NUMBER S 1 2 3 4 5 6 CONTROL BYTE 7 8 9 10 DATA BYTE 11 12 13 14 15 16 17 18 ACK 19 20 21 22 23 24 25 26 27 ACK A4 A3 A2 A1 A0 TX NV V R3 R2 R1 R0 D7 D6 D5 D4 D3 D2 D1 D0 VREG 0 1 0 1 A2 A1 A0 0 0 0 0 1 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 A6 A5 ACK NVREG 0 1 0 1 A2 A1 A0 0 0 0 1 0 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 NVREGxVREG 0 1 0 1 A2 A1 A0 0 0 1 1 0 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 VREGxNVREG 0 1 0 1 A2 A1 A0 0 0 1 0 1 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 P Nonvolatile Memory Positive LCD Bias Control The internal EEPROM consists of an 8-bit nonvolatile register that retains the value written to it before the device is powered down. The nonvolatile register is programmed with the midscale value at the factory. Figures 9 and 10 show an application where the voltage-divider or variable resistor is used to make an adjustable, positive LCD bias voltage. The op amp provides buffering and gain to the resistor-divider network made by the potentiometer (Figure 9) or to a fixed resistor and a variable resistor (see Figure 10). Power-Up Upon power-up, the MAX5417/MAX5418/MAX5419 load the data stored in the nonvolatile memory register into the volatile memory register, updating the wiper position with the data stored in the nonvolatile memory register. This initialization period takes 10s. Standby The MAX5417/MAX5418/MAX5419 feature a low-power standby. When the device is not being programmed, it goes into standby mode and power consumption is typically 500nA. Programmable Filter Figure 11 shows the configuration for a 1st-order programmable filter. The gain of the filter is adjusted by R2, and the cutoff frequency is adjusted by R3. Use the following equations to calculate the gain (G) and the 3dB cutoff frequency (fC): R1 R2 1 fC = 2 x R3 x C G = 1+ Applications Information The MAX5417/MAX5418/MAX5419 are intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control (where voltage biasing adjusts the display contrast), or for programmable filters with adjustable gain and/or cutoff frequency. 5V 5V H 30V 30V W MAX5417 MAX5418 MAx5419 L VOUT H VOUT MAX5417 MAX5418 MAX5419 W L Figure 9. Positive LCD Bias Control Using a Voltage-Divider 12 Figure 10. Positive LCD Bias Control Using a Variable Resistor ______________________________________________________________________________________ 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers 5V VIN L H R3 C MAX5417 MAX5418 MAX5419 VOUT 7 1 3 R1 8 6 MAX410 2 H MAX5417 MAX5418 MAX5419 4 W R2 W -5V L R2 L R1 H Figure 13. Offset Voltage and Gain Adjustment Circuit Figure 11. Programmable Filter Pin Configuration +5V TOP VIEW VIN V0 REF OUT H VDD 1 MAX6160 ADJ MAX5417 MAX5418 MAX5419 8 H W GND SCL 2 L SDA 3 7 W MAX5417 MAX5418 MAX5419 A0 4 V0 = 1.23V 50k FOR THE MAX5417 R2(k) V0 = 1.23V 100k FOR THE MAX5418 R2(k) 200k V0 = 1.23V FOR THE MAX5419 R2(k) Figure 12. Adjustable Voltage Reference Adjustable Voltage Reference Figure 12 shows the MAX5417/MAX5418/MAX5419 used as the feedback resistors in multiple adjustable voltagereference applications. Independently adjust the output voltage of the MAX6160 from 1.23V to VIN - 0.2V by changing the wiper positions of the MAX5417/ MAX5418/MAX5419. 6 L 5 GND TDFN Offset Voltage and Gain Adjustment Connect the high and low terminals of one potentiometer of a MAX5417 between the NULL inputs of a MAX410 and the wiper to the op amp's positive supply to nullify the offset voltage over the operating temperature range. Install the other potentiometer in the feedback path to adjust the gain of the MAX410 (see Figure 13). Chip Information TRANSISTOR COUNT: 4637 PROCESS: BiCMOS ______________________________________________________________________________________ 13 MAX5417/MAX5418/MAX5419 W Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) 6, 8, &10L, DFN THIN.EPS MAX5417/MAX5418/MAX5419 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers D N PIN 1 INDEX AREA E E2 DETAIL A CL CL L A L e e PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY 14 21-0137 ______________________________________________________________________________________ F 1 2 256-Tap, Nonvolatile, I2C-Interface, Digital Potentiometers COMMON DIMENSIONS SYMBOL A MIN. MAX. 0.70 0.80 D 2.90 3.10 E 2.90 3.10 A1 L 0.00 0.05 k 0.40 0.20 0.25 MIN. A2 0.20 REF. PACKAGE VARIATIONS PKG. CODE N D2 E2 e JEDEC SPEC b [(N/2)-1] x e T633-1 6 1.500.10 2.300.10 0.95 BSC MO229 / WEEA 0.400.05 1.90 REF T833-1 8 1.500.10 2.300.10 0.65 BSC MO229 / WEEC 0.300.05 1.95 REF T1033-1 10 1.500.10 2.300.10 0.50 BSC MO229 / WEED-3 0.250.05 2.00 REF T1433-1 14 1.700.10 2.300.10 0.40 BSC ---- 0.200.03 2.40 REF T1433-2 14 1.700.10 2.300.10 0.40 BSC ---- 0.200.03 2.40 REF PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm 21-0137 F 2 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 (c) 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX5417/MAX5418/MAX5419 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)