UNISONIC TECHNOLOGIES CO., LTD

U74HC123

CMOS IC

www.unisonic.com.tw

1 of 10

Copyright © 2015 Unisonic Technologies Co., Ltd

QW-R502-A10.B

DUAL RETRIGGERABLE

MONOSTABLE

MULTIVIBRATOR WITH

RESET



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

Once triggered, the basic output pulse width may be extended

by retriggering the gated active LOW-going edge input( nA ) or

the active HIGH-going edge input (nB). By repeating this process,

SOP-16

TSSOP-16

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

D

nR , which also inhibits the triggering.

An internal connection from

D

nR to the input gates makes it possible to trigger the circuit by a positive-going

signal at input

D

nR as shown in the function table. The basic output pulse width is essentially determined by the

Schmitt-trigger action in the nA 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

Package

Packing

U74HC123G-S16-R

SOP-16

Tape Reel

U74HC123G-P16-R

TSSOP-16

Tape Reel