2004 Fairchild Semiconductor Corporation
DS005338
www.fairchildsemi.com
September 1983
Revised January 2004
M
MM74HC423A
Dual Retriggerable Monostable Multivibrator
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 posi-
tive, 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 trig-
gered 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 out-
put 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.
Features
I
Typical propagation delay: 40 ns
I
Wide power supply range: 2V–6V
I
Low quiescent current: 80
μ
A maximum (74HC Series)
I
Low input current: 1
μ
A maximum
I
Fanout of 10 LS-TTL loads
I
Simple pulse width formula T
=
RC
I
Wide pulse range: 400 ns to
∞
(typ)
I
Part to part variation:
±
5% (typ)
I
Schmitt Trigger A & B inputs allow rise and fall times to
be as slow as one second
Ordering Code:
Note 1:
Devices also available in Tape and Reel. Specify by appending the suffix letter
“
X
”
to the ordering code.
Connection Diagrams
Top View
Timing Component
Note:
Pin 6 and Pin 14 must be hard-wired to GND.
Order Number
MM74HC423AM
(Note 1)
MM74HC423ASJ
MM74HC423AMTC
(Note 1)
MM74HC423AN
Package Number
M16A
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
M16D
MTC16
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide