74HC123-Q100; 74HCT123-Q100
Dual retriggerable monostable multivibrator with reset
Rev. 2 — 19 January 2015
Product data sheet
1. General description
The 74HC123-Q100; 74HCT123-Q100 are high-speed Si-gate CMOS devices and are pin
compatible with Low-power Schottky TTL (LSTTL). They are specified in compliance with
JEDEC standard no. 7A.
The 74HC123-Q100; 74HCT123-Q100 are dual retriggerable monostable multivibrators
with output pulse width control by three methods:
1. The basic pulse is defined by the selection of the external resistor (REXT) and
capacitor (CEXT).
2. 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, the output pulse period (nQ = HIGH, nQ = 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.
3. An internal connection from nRD to the input gates makes it possible to trigger the
circuit by a HIGH-going signal at input nRD as shown in Table 3.
Schmitt trigger action in the nA and nB inputs, makes the circuit highly tolerant to slower
input rise and fall times.
This product has been qualified to the Automotive Electronics Council (AEC) standard
Q100 (Grade 1) and is suitable for use in automotive applications.
2. Features and benefits
Automotive product qualification in accordance with AEC-Q100 (Grade 1)
Specified from 40 C to +85 C and from 40 C to +125 C
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
ESD protection:
MIL-STD-883, method 3015 exceeds 2000 V
HBM JESD22-A114F exceeds 2000 V
MM JESD22-A115-A exceeds 200 V (C = 200 pf, R = 0 )
Specified from 40 C to +85 C and from 40 C to +125 C