Ferreteria

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 PackageOutlines/Information HEF, HEC

HEF4541B MSI Programmable timer
Product specification File under Integrated Circuits, IC04 January 1995

Philips Semiconductors

Product specification

Programmable timerDESCRIPTION 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 andoutput 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 clocksignal 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 HIGHlevel at input MR resets the counter independent on all other inputs. Resetting

HEF4541B MSI
disables the oscillator to provide no active power dissipation. A HIGH at input AR turns off thepower-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 usedrespectively as a single transition timer or 2n frequency divider.

Fig.1 Functional diagram.

HEF4541BP(N): HEF4541BD(F): HEF4541BT(D):

14-lead DIL; plastic (SOT27-1) 14-lead DIL; ceramic (cerdip)(SOT73) 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

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