January 1995 2
Philips Semiconductors Product specification
Dual monostable multivibrator HEF4528B
MSI
DESCRIPTION
The HEF4528B is a dual retriggerable-resettable
monostable multivibrator. Each multivibrator has an active
LOW input (I0), and active HIGH input (I1), an active LOW
clear direct input (CD), an output (O) and its complement
(O), and two pins for connecting the external timing
components (CTC(1), RCTC).
An external timing capacitor (Ct) must be connected
between CTC and RCTC and an external resistor (Rt) must
be connected between RCTC and VDD. The duration of the
(1) Always connected to ground.
output pulse is determined by the external timing
components Ct and Rt.
A HIGH to LOW transition on I0 when I1is LOW or a LOW
to HIGH transition on I1when I0is HIGH produces a
positive pulse (LOW-HIGH-LOW) and O and a negative
pulse (HIGH-LOW-HIGH) on O if the CDis HIGH. A LOW
on CDforces O LOW, O HIGH and inhibits any further
pulses until CDis HIGH.
Fig.1 Functional diagram.
PINNING
FAMILY DATA, IDD LIMITS category MSI
See Family Specifications
HEF4528BP(N): 16-lead DIL; plastic (SOT38-1)
HEF4528BD(F): 16-lead DIL; ceramic (cerdip) (SOT74)
HEF4528BT(D): 16-lead SO; plastic (SOT109-1)
( ): Package Designator North America
I0A, I0B input (HIGH to LOW triggered)
I1A, I1B input (LOW to HIGH triggered)
CDA, CDB clear direct input (active LOW)
OA, OBoutput
OA, OBcomplementary output (active LOW)
CTC A, CTC B external capacitor connections (1)
RCTC A,external capacitor/ resistor connections
RCTC B
Fig.2 Pinning diagram.