hef4538b NXP Semiconductors, hef4538b Datasheet - Page 2

• Manufacturer Part Number: hef4538b
• Description: Dual Precision Monostable Multivibrator
• Manufacturer: NXP Semiconductors

Philips Semiconductors
DESCRIPTION
The HEF4538B is a dual retriggerable-resettable
monostable multivibrator. Each multivibrator has an active
LOW trigger/retrigger input (I
trigger/retrigger input (I
reset input (C
and two pins (C
timing components C
over temperature range is
The HEF4538B may be triggered by either the positive or
the negative edges of the input pulse and will produce an
January 1995
Dual precision monostable multivibrator
D
), an output (O) and its complement (O),
TC
Fig.1 Functional diagram.
,
(1)
t
RC
and R
1
), an overriding active LOW direct
TC
) for connecting the external
t
. Typical pulse width variation
0,2%.
0
), an active HIGH
2
accurate output pulse with a pulse width range of 10 s to
infinity. The duration and accuracy of the output pulse are
determined by the external timing components C
The output pulse width (T) is equal to R
design techniques in LOCMOS guarantee precise control
of the output pulse width.
A LOW level at C
immediately. Schmitt-trigger action in the trigger inputs
makes the circuit highly tolerant to slower rise and fall
times.
PINNING
Note
1. Always connected to ground.
FAMILY DATA, I
See Family specifications.
HEF4538BP(N): 16-lead DIL; plastic (SOT38-1)
HEF4538BD(F):
HEF4538BT(D):
( ): Package Designator North America
I
I
C
O
O
C
RC
0A,
1A
DA
TC A
A
A
, I
, O
, O
TC A
I
, C
0B
1B
, C
B
B
DB
, RC
TC B
TC B
DD
D
Fig.2 Pinning diagram.
16-lead DIL; ceramic (cerdip) (SOT74)
16-lead SO; plastic (SOT109-1)
input (HIGH to LOW triggered)
input (LOW to HIGH triggered)
direct reset input (active LOW)
output
complementary output (active LOW)
external capacitor connections
external capacitor/ resistor
connections
LIMITS category MSI
terminates the output pulse
Product specification
HEF4538B
t
C
t
. The linear
t
MSI
and R
(1)
t
.