M54HC423/423A

M74HC423/423A

October 1993

DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR

B1R

(Plastic Package)

ORDER CODES :

M54HCXXXF1R

M74HCXXXM1R

M74HCXXXB1R

M74HCXXXC1R

F1R

(Ceramic Package)

M1R

(Micro Package)

C1R

(Chip Carrier)

PIN CONNECTIONS (top view)

NC =

No Internal

Connection

.

HIGH SPEED

.

LOW POWER DISSIPATION

.

HIGH NOISE IMMUNITY

.

OUTPUT DRIVE CAPABILITY

10 LSTTL LOADS

.

SYMMETRICAL OUTPUT IMPEDANCE

.

BALANCED PROPAGATION DELAYS

.

WIDE OPERATING VOLTAGE RANGE

.

WIDE OUTPUT PULSE WIDTH RANGE

.

PIN AND FUNCTION COMPATIBLE WITH

54/74LS423

The M54/74HC423/423A are high speed CMOS

MONOSTABLE

multivibrators

fabricated

with

silicon gate C

They achieve the high speed operation similar to

equivalent LSTTL while maintaining the CMOS low

power dissipation. There are two trigger inputs, A

INPUT (negative edge) and B INPUT (positive

edge). These inputs are valid for rising/falling

maintains the MONOSTABLE state for the time

period determined by the external resistor Rx and

capacitor Cx.

Two different pulse width constant are available:

K

≅ 0.46 for HC423

K

≅ 1 for HC423A.

Taking CLR low breaks this MONOSTABLE

STATE. If the next trigger pulse occurs during the

MONOSTABLEperiod it makes the MONOSTABLE

period longer. Limit for values of Cx and Rx :

Cx : NO LIMIT

Ω to 1 M Ω

≥ 3.0 V 1 K Ω to 1 M Ω

All inputs are equipped with protection circuits

against static discharge and transient excess

voltage.

DESCRIPTION

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