Fairchild Semiconductor MM74HC123ASJ, MM74HC123ASJX, MM74HC123AN, MM74HC123AM, MM74HC123AMTC Datasheet

September 1983

Revised February 1999

MM74HC123A

Dual Retriggerable Monostable Multivibrator

General Description

The MM74HC123A high speed monostable multivibrators (one shots) utilize advanced silicon-gate CMOS technology. They feature speeds comparable to low power Schottky TTL circuitry while retaining the low power and high noise immunity characteristic of CMOS circuits.

Each multivibrator features both a negative, A, and a positive, B, transition triggered input, either of which can be used as an inhibit input. Also included is a clear input that when taken low resets the one shot. The MM74HC123A can be triggered on the positive transition of the clear while A is held LOW and B is held HIGH.

The MM74HC123A is retriggerable. That is it may be triggered repeatedly while their outputs are generating a pulse and the pulse will be extended.

Pulse width stability over a wide range of temperature and supply is achieved using linear CMOS techniques. The out-

put pulse equation is simply: PW = (REXT) (CEXT); where PW is in seconds, R is in ohms, and C is in farads. All inputs are protected from damage due to static discharge by diodes to VCC and ground.

Features

■Typical propagation delay: 25 ns

■Wide power supply range: 2V–6V

■Low quiescent current: 80 μA maximum (74HC Series)

■Low input current: 1 μA maximum

■Fanout of 10 LS-TTL loads

■Simple pulse width formula T = RC

■Wide pulse range: 400 ns to ∞ (typ)

■Part to part variation: ±5% (typ)

■Schmitt Trigger A & B inputs enable infinite signal input rise and fall times.

Ordering Code:

Order Number	Package Number	Package Description
MM74HC123AM	M16A	16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow
MM74HC123ASJ	M16D	16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MM74HC123AMTC	MTC16	16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
MM74HC123AN	N16E	16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram	Timing Component
Pin Assignment for DIP, SOIC, SOP and TSSOP

Note: Pin 6 and Pin 14 must be hard-wired to GND.

Top View

Multivibrator Monostable Retriggerable Dual MM74HC123A

© 1999 Fairchild Semiconductor Corporation

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MM74HC123A

Truth Table

H = HIGH Level

L = LOW Level

− = Transition from LOW-to-HIGH ↓ = Transition from HIGH-to-LOW

= One HIGH Level Pulse

= One LOW Level Pulse X = Irrelevant

Logic Diagram

	Inputs					Outputs
	Clear		A	B	Q			Q
	L		X	X	L			H
	X		H	X	L			H
	X		X	L	L			H
	H		L	−
	H		↓	H
	−		L	H

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Absolute Maximum Ratings(Note 1)

(Note 2)
Supply Voltage (VCC)	−0.5V to +7.0V
DC Input Voltage (VIN)	−1.5V to VCC +1.5V
DC Output Voltage (VOUT)	−0.5V to VCC +0.5V
Clamp Diode Current (IIK, IOK)	±20 mA
DC Output Current, per pin (IOUT)	±25 mA
DC VCC or GND Current, per pin (ICC)	±50 mA
Storage Temperature Range (TSTG)	−65°C to +150°C
Power Dissipation (PD)
(Note 3)	600 mW
S.O. Package only	500 mW
Lead Temperature (TL)	260°C
(Soldering 10 seconds)

Recommended Operating

Conditions

	Min	Max	Units
Supply Voltage (VCC)	2	6	V
DC Input or Output Voltage	0	VCC	V
(VIN, VOUT)	−40	+85	°C
Operating Temperature Range (TA)
Input Rise or Fall Times
(Clear Input)
(tr, tf) VCC = 2.0V		1000	ns
VCC = 4.5V		500	ns
VCC = 6.0V		400	ns

Note 1: Maximum Ratings are those values beyond which damage to the device may occur.

Note 2: Unless otherwise specified all voltages are referenced to ground.

Note 3: Power Dissipation Temperature Derating: Plastic “N” Package: − 12mW/°C from 65°C to 85°C

DC Electrical Characteristics			(Note 4)
Symbol	Parameter	Conditions	VCC	TA = 25°C		TA = −40 to 85°C	TA = −55 to 125°C	Units
				Typ		Guaranteed Limits
VIH	Minimum HIGH Level Input		2.0V		1.5	1.5	1.5	V
	Voltage		4.5V		3.15	3.15	3.15	V
			6.0V		4.2	4.2	4.2	V
VIL	Maximum LOW Level Input		2.0V		0.3	0.3	0.3	V
	Voltage		4.5V		0.9	0.9	0.9	V
			6.0V		1.2	1.2	1.2	V
VOH	Minimum HIGH Level	VIN = VIH or VIL
	Output Voltage	|IOUT| ≤ 20 μA	2.0V	2.0	1.9	1.9	1.9	V
			4.5V	4.5	4.4	4.4	4.4	V
			6.0V	6.0	5.9	5.9	5.9	V
		VIN = VIH or VIL						V
		|IOUT| ≤ 4.0 mA	4.5V	4.2	3.98	3.84	3.7	V
		|IOUT| ≤ 5.2 mA	6.0V	5.7	5.48	5.34	5.2	V
VOL	Maximum LOW Level	VIN = VIH or VIL
	Output Voltage	|IOUT| ≤ 20 μA	2.0V	0	0.1	0.1	0.1	V
			4.5V	0	0.1	0.1	0.1	V
			6.0V	0	0.1	0.1	0.1	V
		VIN = VIH or VIL						V
		|IOUT| ≤ 4 mA	4.5V	0.2	0.26	0.33	0.4	V
		|IOUT| ≤ 5.2 mA	6.0V	0.2	0.26	0.33	0.4	V
IIN	Maximum Input Current	VIN = VCC or GND	6.0V		±0.5	±5.0	±5.0	μA
	(Pins 7, 15)
IIN	Maximum Input Current	VIN = VCC or GND	6.0V		±0.1	±1.0	±1.0	μA
	(all other pins)
ICC	Maximum Quiescent Supply	VIN = VCC or GND	6.0V		8.0	80	160	μA
	Current (standby)	IOUT = 0 μA
ICC	Maximum Active Supply	VIN= VCC or GND	2.0V	36	80	110	130	μA
	Current (per	R/CEXT = 0.5VCC	4.5V	0.33	1.0	1.3	1.6	mA
	monostable)		6.0V	0.7	2.0	2.6	3.2	mA

Note 4: For a power supply of 5V ±10% the worst-case output voltages (VOH, VOL) occur for HC at 4.5V. Thus the 4.5V values should be used when designing with this supply. Worst-case VIH and VIL occur at VCC = 5.5V and 4.5V respectively. (The VIH value at 5.5V is 3.85V.) The worst-case leakage current (IIN, ICC, and IOZ) occur for CMOS at the higher voltage and so the 6.0V values should be used.

MM74HC123A

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