MM54HC423A/MM74HC423A
Dual Retriggerable Monostable Multivibrator
General Description
The MM54/74HC423A 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 'HC423A cannot
be triggered from clear.
The 'HC423A is retriggerable. That is, it may be triggered
repeatedly while its 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 output
pulse equation is simply: PWe(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.