MM54HC123A  Product Folder

The MM54/74HC123A 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 'HC123 can be triggered on the positive transition of the clear while A is held low and B is held high.

The 'HC123A 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 output pulse equation is simply: PW=(R_EXT) (C_EXT); 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 V_CC and ground.

• 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 [Infinity] (typ)
• Part to part variation: ±5% (typ)
• Schmitt Trigger A & B inputs enable infinite signal input rise and fall times.