HD74LS123 Datasheet, PDF (2/9 Pages) Hitachi Semiconductor – Dual Retriggerable Monostable Multivibrators(with Clear)

HD74LS123
Pin Arrangement
1A 1
1B 2
1CLR 3
1Q 4
2Q 5
2Cext 6
2Rext/Cext 7
GND 8
CLR
QQ
QQ
CLR
16 V_CC
15 _1Rext/Cext
14 _1Cext
13 _1Q
12 _2Q
11 _2CLR
10 _2B
9 2A
(Top view)
Function Table
Inputs
Clear
A₁
L
X
X
H
X
X
H
L
H
↓
↑
L
Notes: H; high level, L; low level, X; irrelevant
↑; transition from low to high level
↓; transition from high to low level
; one high-level pulse
; one low-level pulse
Block Diagram (1/2)
B₂
X
X
L
↑
H
H
External parameter
Outputs
Q
Q
L
H
L
H
L
H
A
B
Clear
Cext Rext V_CC
/Cext
QQ
QQ
Clear
Rev.2.00, Feb.18.2005, page 2 of 8