UNISONIC TECHNOLOGIES CO., LTD U74HC123 CMOS IC DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR WITH RESET SOP-16 DESCRIPTION The U74HC123 is high-speed Si-gate CMOS device and is pin compatible with low power Schottky TTL (LSTTL). The U74HC123 is a dual retriggerable monostable multivibrator with output pulse width control by three methods. The basic pulse time is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be extended TSSOP-16 by retriggering the gated active LOW-going edge input( n A ) or the active HIGH-going edge input (nB). By repeating this process, the output pulse period (nQ=HIGH, n Q =LOW) can be made as long as desired. Alternatively an output delay can be terminated at any time by a LOW-going edge on input nRD , which also inhibits the triggering. An internal connection from nRD to the input gates makes it possible to trigger the circuit by a positive-going signal at input nRD as shown in the function table. The basic output pulse width is essentially determined by the values of the external timing components REXT and CEXT. Schmitt-trigger action in the n A and nB inputs, makes the circuit highly tolerant to slower input rise and fall times. FEATURES * DC triggered from active HIGH or active LOW inputs * Retriggerable for very long pulses up to 100% duty factor * Direct reset terminates output pulse * Schmitt-trigger action on all inputs except for the reset input ORDERING INFORMATION Ordering Number U74HC123G-S16-R U74HC123G-P16-R www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd Package SOP-16 TSSOP-16 Packing Tape Reel Tape Reel 1 of 10 QW-R502-A10.B U74HC123 CMOS IC MARKING PIN CONFIGURATION FUNCTION TABLE INPUTS OUTPUTS nQ nQ L X X nA X H X nB X X L L L(2) L(2) H H(2) H(2) H L ↑ H ↓ H ↑ L H nRD Notes: 1. H: HIGH voltage level L: LOW voltage level X: don’care ↑: LOW-to-HIGH transition ↓: HIGH-to-LOW transition : one HIGH level output pulse : one LOW level output pulse 2. If the monostable was triggered before this condition was established, the pulse will continue as programmed. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 10 QW-R502-A10.B U74HC123 CMOS IC LOGIC SYMBOL UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 10 QW-R502-A10.B U74HC123 CMOS IC LOGIC DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 10 QW-R502-A10.B U74HC123 CMOS IC ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Supply Voltage VCC -0.5 ~ 7 V VCC or GND Current ICC ±50 mA Output Current IOUT ±25 mA Input Clamp Current IIK ±20 mA Output Clamp Current IOK ±20 mA Storage Temperature TSTG -65 ~ + 150 °C Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. RECOMMENDED OPERATING CONDITIONS PARAMETER Supply Voltage High-level Input Voltage Low-level Input Voltage Input Voltage Output Voltage Input Transition Rise and Fall Rate nRD Input Ambient Temperature SYMBOL VCC VIH VIL TEST CONDITIONS VCC=2V VCC=4.5V VCC=6V VCC=2V VCC=4.5V VCC=6V MIN 2 1.5 3.15 4.2 VIN VOUT △t/△V TYP 5 1.2 2.4 3.2 0.8 2.1 2.8 0 0 VCC=2V VCC=4.5V VCC=6V MAX UNIT 6 V V 0.5 1.35 1.8 VCC VCC 1000 500 400 +125 V V V ns -40 +25 MIN 1.9 4.4 5.9 3.98 5.48 TYP MAX UNIT 2 4.5 V 6 4.32 5.81 0 0.1 0 0.1 V 0 0.1 0.15 0.26 0.16 0.26 ±0.1 μA 8 μA 3.5 pF Tamb °C ELECTRICAL CHARACTERISTICS (TA =25°C , unless otherwise specified) PARAMETER SYMBOL Output Voltage High-Level VOH Output Voltage Low-Level VOL Input Leakage Current Quiescent Supply Current Input Capacitance II(LEAK) ICC CI TEST CONDITIONS VCC=2V, IOH=-20μA VCC=4.5V, IOH=-20μA VCC=6V, IOH=-20μA VCC=4.5V, IOH=-4mA VCC=6V, IOH=-5.2mA VCC=2V, IOL=20μA VCC=4.5V, IOL=20μA VCC=6V, IOL=20μA VCC=4.5V, IOL=4mA VCC=6V, IOL=5.2mA VCC=6V, VIN= VCC or GND VCC=6V, VIN=VCC or GND, IOUT=0 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 10 QW-R502-A10.B U74HC123 CMOS IC SWITCHING CHARACTERISTICS (tr = tf = 6ns, CL=50pF, TA =25°C, unless otherwise specified) PARAMETER Propagation Delay Time From n A , nB to nQ or n Q Propagation Delay Time From nRD to nQ or n Q SYMBOL tPLH/tPHL tPLH/tPHL Output transition time tt Trigger pulse width n A =LOW tw Trigger pulse width nB=HIGH tw Reset pulse width nRD =LOW tw Output pulse width TEST CONDITIONS VCC=2V VCC=4.5V CEXT=0pF REXT=5k VCC=5V, CL=15p VCC=6V VCC=2V VCC=4.5V CEXT=0pF REXT=5k VCC=5V, CL=15p VCC=6V VCC=2V VCC=4.5V VCC=6V VCC=2V VCC=4.5V VCC=6V VCC=2V VCC=4.5V VCC=6V VCC=2V VCC=4.5V VCC=6V MIN 100 20 17 100 20 17 100 20 17 TYP 83 30 26 24 66 24 20 19 19 7 6 8 3 2 17 6 5 14 5 4 MAX UNIT 255 51 ns 43 215 43 37 75 15 13 ns ns ns ns ns tw VCC=5V , CEXT=100nF, REXT=10k 450 μs tw VCC=5V , CEXT=0pF, REXT=5k 75 ns Retrigger time n A , nB trt VCC=5V , CEXT=0pF, REXT=5k 110 ns External timing resistor REXT External timing capacitor CEXT nQ=HIGH, n Q =LOW Output pulse width nQ=HIGH, n Q =LOW VCC=2V VCC=5V VCC=5V 10 2 2 1000 1000 10000 kΩ pF OPERATING CHARACTERISTICS (TA =25°C , unless otherwise specified) PARAMETER Power Dissipation Capacitance Per monostable SYMBOL CPD UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw TEST CONDITIONS MIN TYP 54 MAX UNIT pF 6 of 10 QW-R502-A10.B U74HC123 CMOS IC TEST CIRCUIT AND WAVEFORMS UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 10 QW-R502-A10.B U74HC123 CMOS IC TEST CIRCUIT AND WAVEFORMS(Cont.) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 10 QW-R502-A10.B U74HC123 CMOS IC APPLICATION INFORMATION Timing component connections The basic output pulse width is essentially determined by the values of the external timing components REXT and CEXT. Power-up considerations When the monostable is powered-up it may produce an output pulse, with a pulse width defined by the values of REXT and CEXT, this output can be eliminated using the circuit below. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 10 QW-R502-A10.B U74HC123 CMOS IC APPLICATION INFORMATION(Cont.) Power-down considerations A large capacitor (CEXT) may cause problems when powering-down the monostable due to the energy stored in this capacitor. When a system containing this device is powered-down or a rapid decrease of VCC to zero occurs, the monostable may substain damage, due to the capacitor discharging through the input protection diodes. To avoid this possibility, use a damping diode (DEXT) preferably a germanium or Schottky type diode able to withstand large current surges and connect as shown below. UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 10 of 10 QW-R502-A10.B