CD54HC221_07 Datasheet, PDF (2/22 Pages) Texas Instruments – High-Speed CMOS Logic Dual Monostable Multivibrator with Reset

CD54HC221, CD74HC221, CD74HCT221
Functional Diagram
1C_X 1R_X
14
15
V_CC
1C_X
1C_XR_X
13
1A
1Q
1
MONO 1
4
1B
1Q
2
1R
3
11
2R
9
2A
10
2B
MONO 2
5
2Q
12
2Q
2C_X
6
2C_XR_X
7
2C_X 2R_X
V_CC
TRUTH TABLE
INPUTS
A
B
R
H
X
H
X
L
H
L
↑
H
OUTPUTS
Q
Q
L
H
L
H
↓
H
H
X
X
L
L
H
L
H
↑
(Note 3)
(Note 3)
H = High Voltage Level, L = Low Voltage Level, X = Irrelevant, ↑ = Transition from
Low to High Level, ^↓ = Transition from High to Low Level,
= One High Level
Pulse,
= One Low Level Pulse
NOTE:
1. For this combination the reset input must be low and the following sequence
must be used: pin 1 (or 9) must be set high or pin 2 (or 10) set low; then pin 1
(or 9) must be low and pin 2 (or 10) set high. Now the reset input goes from low-
to-high and the device will be triggered.
2