CD4538BC Datasheet, PDF (1/10 Pages) Fairchild Semiconductor – Dual Precision Monostable

February 1988
CD4538BM CD4538BC Dual Precision Monostable
General Description
The CD4538B is a dual precision monostable multivibrator
with independent trigger and reset controls The device is
retriggerable and resettable and the control inputs are inter-
nally latched Two trigger inputs are provided to allow either
rising or falling edge triggering The reset inputs are active
low and prevent triggering while active Precise control of
output pulse-width has been achieved using linear CMOS
techniques The pulse duration and accuracy are deter-
mined by external components R_X and C_X The device does
not allow the timing capacitor to discharge through the tim-
ing pin on power-down condition For this reason no exter-
nal protection resistor is required in series with the timing
pin Input protection from static discharge is provided on all
pins
Features
Y _{Wide supply voltage range}
3 0V to 15V
Y _{High noise immunity}
Y _{Low power}
TTL compatibility
0 45 V_CC (typ )
Fan out of 2 driving 74L
or 1 driving 74LS
Y _{New formula PWOUT} e _RC
(PW in seconds R in Ohms C in Farads)
Y g_{1 0% pulse-width variation from part to part (typ )}
Y _{Wide pulse-width range}
1 ms to %
Y _{Separate latched reset inputs}
Y _{Symmetrical output sink and source capability}
Y _{Low standby current}
Y _{Pin compatible to CD4528B}
5 nA (typ )
5 V_DC
Block and Connection Diagrams
Dual-In-Line Package
CD4538BM
CD4538BC
Top View
Order Number CD4538B
R_X and C_X are External Components
V_DD e Pin 16
V_SS e Pin 8
Truth Table
TL F 6000 – 1
Inputs
Clear
A
B
L
X
X
X
H
X
X
X
L
H
Lv
H
uH
Outputs
Q
Q
L
H
L
H
L
H
H e High Level
L e Low Level
u e Transition from Low to High
v e Transition from High to Low
e One High Level Pulse
e One Low Level Pulse
X e Irrelevant
TL F 6000 – 2
C1995 National Semiconductor Corporation TL F 6000
RRD-B30M105 Printed in U S A