MM74HC423A

Typical propagation delay: 40 ns
Wide power supply range: 2V6V
Low quiescent current: 80 A maximum (74HC Series)
Low input current: 1 A 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

Supply Voltage (VCC)                                                       −0.5V to +7.0V
DC Input Voltage (VIN)                                             −1.5V to VCC +1.5V
DC Output Voltage (VOUT)                                        −0.5V to VCC +0.5V
Clamp Diode Current (IIK, IOK)                                                   ±20 mA
DC Output Current, per pin (IOUT)                                              ±25 mA
DC VCC or GND Current,
per pin (ICC)                                                                                ±50 mA
Storage Temperature Range (TSTG)                                 −65to +150
Power Dissipation (PD)
(Note 4)                                                                                        600 mW
S.O. Package only                                                                         500 mW
Lead Temperature (TL)
(Soldering 10 seconds)                                                                     260

The MM74HC423A 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 MM74HC423A 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.

Pulse width stability of MM74HC423A over a wide range of temperature and supply is achieved using linear CMOS techniques. The output pulse equation is simply: PW = (REXT) (CEXT); where PW

is in seconds, R is in ohms, and C is in farads. All inputs of MM74HC423A are protected from damage due to static discharge by diodes to VCC and ground.