HD74HC4538 Datasheet, PDF (10/16 Pages) Hitachi Semiconductor – Dual Precision Retriggerable/Resettable Monostable Multivibrators

HD74HC4538
Quiescent
State Trigger Cycle (A Input) Trigger Cycle (B Input)
Reset
7
Trigger Input A
(Pin 4 or 12)
Trigger Input B
(Pin 5 or 11)
Reset Input CD
(Pin 3 or 13)
8
21
Retrigger
trr
9
Trigger-Control
3
Circuit Output
4
T2 Input
12
(Pin 2 or 14)
14
11
15
Vref Lower 13
Upper Reference 5
Circuit Output
13
Lower Reference 6
16
Circuit Output
17
Vref Upper
Reset Latch
1
Output
10
Q Output
2
19
(Pin 6 or 10)
tWQ
tWQ
24
20 23
25
22
tWQ+trr
tW (H)
A
50%
tW (L)
B
tPLH
Q
tWQ
50%
tPHL
50%
tPLH
tPHL
Q
50%
A
trr
B
tf
CD
50%
tTLH
Q
90%
10%
tTHL
tPLH
Q
90%
10%
tr
tW (L)
90%
10%
tPHL
50%
50%
50%
50%
tWQ+trr
(Retriggered Pulse)
Fig. 2 Timing Diagram
10