Am556 Dual Precision Tim r Distinctive Characteristics Timing from microseconds through hours 200mA output sink current Variable duty cycle @ TTL output compatibility Temperature stability of 0.005%/C @ Replaces two Am555's @ 100% reliability assurance testing in compliance with MIL-STD-883. FUNCTIONAL DESCRIPTION The Am556 1s a dual highly stable timing device used to provide accurate time delays or to build precision oscillators. The Am556 ts a dual Am555, where the two timers operate independently of each other sharing only Vec and GND. When either timer is used as a monostable, the time ts precisely controlfed using one external resistor and one ex- ternal capacitor. When the timer is used as a precision oscillator, the frequency and duty cycle are controlled by two external resistors and one external capacitor. For monostable operation, a HIGH-to-LOW transition is applied to the trigger input, The device 1s triggered when the input trigger voltage reaches 1/3 Vec Once the circuit Is triggered, It will remain in the triggered state unttl the set time has elapsed, even if it 1s triggered again The output pulse width ts equal to 1.1 Rac. For continuous oscillation, two external resistors are used such that the external capacitor charges and discharges be- tween 1/3 Veco and 2/3 Voc. The charge time is given by tcharge = 0693 (Ra + RgiC while the discharge time is taischarge = 0.693 RaC (See Fig 3) Each timer also features a direct reset that overrides all other inputs. When the reset 1s LOW the output is LOW regardless of the other inputs. SCHEMATIC DIAGRAM (One Timer Shown) LOGIC SYMBOL PK CONTROL FLIP FLOP FLIP FLOP CONTROL DISCHARGE DISCHARGE THRESHOLD THRESKOLD RESET RESET VOLTAGE 5 OUTPUT VOLTAGE OUTPUT 518) 4 airy 9 SONTROL 1 VOLTAGE Voc O ; 47K a30n aTkR 2 1kQ - BHKN see ry THRESHOLD LL 2 2172) fo 7K 5k 10k2. 47kQ \_ TRIGGER s(a) RESET a(10) 220. DISCHARGE 113} GND + 00 Sk2 7 ka I L L of 44 1002 47kQ TRIGGER TRIGGER OUTPUT Vec = Pin 14 GND =Pin7? ORDERING INFORMATION Package Temperature Order Type Range Number Molded DIP 0C to +70C NES5S6A vw Hermetic DIP 0C ta +70C NESS56F Dice 0C to +70C AM556XC Hermetic DIP 55C to+125C SE556F Dice 55C to+125C + AM556XM CONNECTION DIAGRAM Top View DISCHARGE oO 14 T] Yeo THRESHOLO [_] 2 13 V1 OISCHARGE CONTROL [4 3 VOLTAGE 12 J THRESHOLD CONTROL reset [[] 4 ames 11 CONTROL output [Js vo [_} Reset triccer (_] 6 9 [_) output cwo (7 8 TRIGGER Note Pin 711s marked for orientationAm 556 MAXIMUM RATINGS (Above which the useful life may be impatred) Storage Temperature 68C to +150C Temperature (Ambient) Under Bias Military Grade Commercial Grade 55C to +125C 0C to +70C Supply Voltage to Ground Potential +18V Power Dissipatian 600mW Lead Temperature (Soldering, 60 Seconds} +300C ELECTRICAL CHARACTERISTICS (Ta = 25C, Vcc = 5V to 15V Unless Otherwise Spectfied} Military Commercial Parameter Test Conditions Min Typ. Max. Min. Typ. Max. Units Supply Voltage 45 18 45 16 Vv Supply Current Voc =5V, RL = 3 5 3 6 mA LOW State (Per Timer) Vec = 18V, RL = 10 W 10 14 mA Threshold Voltage 2/3 2/3 XVec Threshold Current Note 3 30 100 30 100 nA Voc = 15V 48 5 52 5 Vv Trigger Voltage Voc = SV 145.) 167 | 19 1 67 Vv Trigger Current 05 05 uA Reset Voltage 04 07 10 04 O7 10 Vv Reset Current 01 01 mA Voc = 15V 96 10 104 90 10 11 v Control Voltage Level Veo =5V 29 333 3B 26 333 4 Vv ISINK = 10mA 01 015 01 025 Vv Veg = 15V ISINK = 50mA 04 os a4 075 Vv ISINK = 100mA 20 225 20 275 Vv Output Voltage (LOW) IsINK = 200mA 25 25 Vv Vee =8V Isink = 8mA o1 | 025 v ISINK = 5mA 025 035 Vv Voc = 15V ISOURCE = 200mA 125 125 v Output Voltage (HIGH) Vec = 15V IsoURCE = 100ma |_13.0 133 1275 | 133 v Voc = 5V 30 33 275 33 v Rise Time of Output 100 100 ns Fall Time of Output 100 100 ns Timing Error (Monostable} Inttial Accuracy Ra = 2K to 100K 05 15 075 % Drift with Temperature C =O tuF (Note 2) 30 100 50 ppm/C Onift with Supply Voltage 005 02 01 %/Volt Timing Error {Astabie) tnitial Accuracy Ra. Rg = 2K to 100K 15 225 % Drift with Temperature C = 0 1uF (Note 2} 90 150 ppm/C Onft with Supply Voltage 015 03 %/Volt Discharge Leakage Current 20 100 20 100 nA Matching Characteristics (Note 4) {nitral Timing Accuracy 005 01 01 02 % Timing Drift with Temperature +10 +10 ppm/ Drift with Supply Voltage 01 02 02 0s KIVolt Notes Supealy current when output rs high ts typically 1 OMA less Tested at Vocg = SV and Voc = 15V 1 2 3. This will determine maximum value of Ra + Re for 15V operation The max total R = 20 Meg 2 4 Matching characteristics refer to the differences between performance characteristics of each timer saction 86Am556 Minimum Pulse Width Required for Triggering MINIMUM PULSE WLDTH nsec 470C + 0 a 01 02 03 O4 LOWEST VOLTAGE LEVEL OF TRIGGER PULSE ~ XVcq Low Output Voltage Versus Output Sink Current Vout VOUTS 10 10 Isink A Delay Time Versus Supply Voltage 1015 1010 1000 Os95 NORMALIZED DELAY TIME a9s0 0985 o 5 SUPPLY VOLTAGE ~ VOLTS 10 15 20 TYPICAL CHARACTERISTICS Supply Current Versus Supply Voltage SUPPLY CURRENT mA Vee - Vout VOLTS SUPPLY VOLTAGE ~ VOLTS Low Output Voltage Versus Output Sink Current 10 Veg = 10v 425C a o 5 10 5 g 8 1 | E +425C +925C- E 2 2 S01 2 001 1 'siInK ~ mA Delay Time Versus Temperature 1015 2 1010 j = I > > = 1.005 4 3 a 2 1000 5 5 @ a = 0995 9 z oO oO z 0990 c 0.985 -50 ~25 0 25 50 75 AMBIENT TEMPERATURE C 100 125 LOWEST VOLTAGE LEVEL OF TRIGGER PULSE XVcec High Output Voltage Versus Output Source Current SV S Voges I5V 10 Isource A 100 Low Output Voltage Versus Output Sink Current 10 Veg = 15V 01 on sink ~ mA Propagation Delay Versus Voltage Level of Trigger Pulse +1 +25C +70C 0 0 01 02 a3 oa 8-7Am556 APPLICATIONS MONOSTABLE OPERATION When the timer is operated as a monostable multivibrator, one external capacitor, C, and one external resistar, Ra, are used as shown in Figure 1 When the trigger input is reduced below 1/3 Vcc, the timer internal flip-flop is set This releases the short circuit across the external capacitor as the O output goes HIGH The voltage across the capacitor begins to rise exponentially with the time constant RaC When the capacitor voltage reaches 2/3 Vcc, the internal comparator resets the internal flip-flap and discharges the external capacitor, C, very rapidly The output is now tn LOW state and a new timing state may be initiated The time that the output is in the HIGH state is given by 1 1 RaC or can be taken directly from Figure 2 Both the charge rate and internal threshold are directly proportional to the Vcc supply voltage Thus, the timer output pulse width is independent of the power supply voltage If a LOW is applied to the reset input, the output 1s forced LOW and the external capacitor discharged regardless of the other inputs. Veo RESET | a 14 Ra 6] vay, RI ce TRIGGER THRESHOLD 1 OISCHARGE 23 V60 12 THRESHOLD AmS56 5 OUTPUT Fig 1. Monostable Operation of the Am556. 100 tet TRac 10 we a | wy 10 & Zz 1 < E 5 91 i 4 i 8 001 1 t 001 10. 100 1 10 100 1 10 usec sec =omset msec msec sec set TIME DELAY (QUTPUT HIGH} Fig. 2. Monostable Pulse Width Graph. ASTABLE OPERATION When the timer ts operated in the astable mode, two ex- ternal resistors, Ra and Rg, and one externa! capacitor, C, are used as shown in Figure 3 With this connection scheme, the external capacitor, C, charges and discharges between 1/3 Vcc and 2/3 Vec The charge time (output HIGH) ts tag = 0693 (Ra + Rg) Cc The discharge time (output LOW) 1s tg = 0 693 RgC The total period for one cycle of output HIGH and output LOW 5s T= tap t tg = 0 693 (Ra + 2R_) C The frequency for this period, T, ts 1 0 693 (Ra +2RR) C al. T The astable free running frequency can also be found from the graph shown in Figure 4 The duty cycle, time the out- put 1s LOW divided by the period, is given by D= tee Re tag + te Ra + 2Rg Voc 14 t Ra 1 3 RESET DISCHARGE 2, 2 AmS86 THRESHOLD $"a ouTeut 5 U3 Vee LS THRESHOLD 7 3 ac [ = i l Fig. 3. Astable Operation of the Am556. 100 te 144 Tay + 2Ag) Cc 10 At 2Re uo % ! w 10 oO Zz ft E 6 01 < a xt oO 001 Rat 2Rg 0.001 o1 10 10 100 1k 10k FREE RUNNING FREQUENCY ~ Hz 100k Fig. 4. Astable Free Running Frequency. | DISCHARGE THRESHOLD CONTROL VOLTAGE RESET OUTPUT Metallization and Pad Layout DISCHARGE THRESHOLD CONTROL VOLTAGE RESET OUTPUT TRIGGER TRIGGER BIE SIZE 0 060" X 0074 8-8