Philips HEF4541BU, HEF4541BT, HEF4541BPB, HEF4541BP, HEF4541BDB Datasheet

INTEGRATED CIRCUITS

DATA SHEET

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

HEF4541B

MSI

Programmable timer

Product specification			January 1995
File under Integrated Circuits, IC04

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 Rt and Ct within 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, 213 or 216 depending 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 2n frequency divider.

Fig.1 Functional diagram.

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

FAMILY DATA, IDD LIMITS category MSI

Fig.2 Pinning diagram.

See Family Specifications

January 1995

2

Philips Semiconductors	Product specification

Programmable timer

HEF4541B

MSI

Fig.3 Logic diagram.

January 1995

3