CD4538BC Datasheet, PDF (1/11 Pages) Fairchild Semiconductor – Dual Precision Monostable

October 1987
Revised January 1999
CD4538BC
Dual Precision Monostable
General Description
The CD4538BC is a dual, precision monostable multivibra-
tor with independent trigger and reset controls. The device
is retriggerable and resettable, and the control inputs are
internally 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 lin-
ear CMOS techniques. The pulse duration and accuracy
are determined by external components R_X and C_X. The
device does not allow the timing capacitor to discharge
through the timing pin on power-down condition. For this
reason, no external protection resistor is required in series
with the timing pin. Input protection from static discharge is
provided on all pins.
Features
s Wide supply voltage range: 3.0V to 15V
s High noise immunity: 0.45 V_CC (typ.)
s Low power TTL compatibility: Fan out of 2 driving 74L
or 1 driving 74LS
s New formula: PW_OUT = RC (PW in seconds, R in Ohms,
C in Farads)
s ±1.0% pulse-width variation from part to part (typ.)
s Wide pulse-width range: 1 µs to ∞
s Separate latched reset inputs
s Symmetrical output sink and source capability
s Low standby current: 5 nA (typ.) @ 5 V_DC
s Pin compatible to CD4528BC
Ordering Code:
Order Number Package Number
Package Description
CD4538BCM
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body
CD4538BCWM
M16B
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
CD4538BCN
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Truth Table
Pin Assignments for DIP and SOIC
Top View
Inputs
Outputs
Clear
A
B
Q
Q
L
X
X
L
H
X
H
X
L
H
X
H
H
X
L
↑
L
L
H
 ↓
 H
H = HIGH Level
L = LOW Level
↑ = Transition from LOW-to-HIGH
 ↓ = Transition from HIGH-to-LOW
= One HIGH Level Pulse
= One LOW Level Pulse
X = Irrelevant
© 1999 Fairchild Semiconductor Corporation DS006000.prf
www.fairchildsemi.com