
Fairchild Semiconductor
General Description
The 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 MM74HC423A cannot be triggered from clear.
The MM74HC423A is retriggerable. That is, it may be triggered repeatedly while its outputs are generating a pulse and the pulse will be extended.
FEATUREs
■ Typical propagation delay: 40 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 allow rise and fall times to be as slow as one second