DATA SH EET
Product specification
File under Integrated Circuits, IC04
January 1995
INTEGRATED CIRCUITS
HEF4541B
MSI
Programmable timer
For a complete data sheet, please also download:
•The IC04 LOCMOS HE4000B Logic
Family Specifications HEF, HEC
•The IC04 LOCMOS HE4000B Logic
Package Outlines/Information HEF, HEC
January 1995 2
Philips Semiconductors Product specification
Programmable timer
HEF4541B
MSI
DESCRIPTION
The HEF4541B is a programmable timer which consists of
a 16-stage binary counter, an integrated oscillator to be
used with external timing components, an automatic
power-on reset and output control logic. The frequency of
the oscillator is determined by the external components
Rtand Ctwithin the frequency range 1 Hz to 100 kHz. This
oscillator may be replaced by an external clock signal at
input RS, the timer advances on the positive-going
transition of RS. A LOW on the auto reset input (AR) and
a LOW on the master reset input (MR) enables the internal
power-on reset. A HIGH level at input MR resets the
counter independent on all other inputs. Resetting
disables the oscillator to provide no active power
dissipation.
A HIGH at input
AR turns off the power-on reset to provide
a low quiescent power dissipation of the timer. The
16-stage counter divides the oscillator frequency by
28,210,213or 216depending on the state of the address
inputs (A0,A1). The divided oscillator frequency is
available at output O. The phase input (PH) features a
complementary output signal. If the mode select input
(MODE) is LOW or HIGH the timer can be used
respectively as a single transition timer or 2nfrequency
divider.
Fig.1 Functional diagram.
Fig.2 Pinning diagram.
FAMILY DATA, IDDLIMITS category MSI
See Family Specifications
HEF4541BP(N): 14-lead DIL; plastic
(SOT27-1)
HEF4541BD(F): 14-lead DIL; ceramic (cerdip)
(SOT73)
HEF4541BT(D): 14-lead SO; plastic
(SOT108-1)
( ): Package Designator North America
January 1995 3
Philips Semiconductors Product specification
Programmable timer
HEF4541B
MSI
Fig.3 Logic diagram.