74HC123 Datasheet, PDF (4/17 Pages) NXP Semiconductors – Dual retriggerable monostable multivibrator with reset

Philips Semiconductors
Dual retriggerable monostable
multivibrator with reset
Product specification
74HC/HCT123
Fig.4 Functional diagram.
FUNCTION TABLE
INPUTS
OUTPUTS
nR_D nA nB
LX X
XH X
XX L
HL
↑
nQ
L
L⁽¹⁾
L⁽¹⁾
nQ
H
H⁽¹⁾
H⁽¹⁾
H↓
H
↑L
H
Note
1. If the monostable was triggered
before this condition was
established, the pulse will
continue as programmed.
H = HIGH voltage level
L = LOW voltage level
X = don’t care
↑ = LOW-to-HIGH transition
↓ = HIGH-to-LOW transition
= one HIGH level output pulse
= one LOW level output pulse
(1) For minimum noise generation,
it is recommended to ground pins 6 (2C_EXT)
and 14 (1C_EXT) externally to pin 8 (GND).
1998 Jul 08
Fig.5 Logic diagram.
4