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