HEF4521BPB 查看數據表（PDF） - Philips Electronics

零件编号

产品描述 (功能)

生产厂家

HEF4521BPB

24-stage frequency divider and oscillator

Philips Electronics 

Philips Semiconductors

24-stage frequency divider and oscillator

Product specification

HEF4521B

MSI

DESCRIPTION

The HEF4521B consists of a chain of 24 toggle flip-flops

with an overriding asynchronous master reset input (MR),

and an input circuit that allows three modes of operation.

The single inverting stage (I2/O2) will function as a crystal

oscillator, or in combination with I1 as an RC oscillator, or

as an input buffer for an external oscillator. Low-power

operation as a crystal oscillator is enabled by connecting

external resistors to pins 3 (VSS’) and 5 (VDD’).

Each flip-flop divides the frequency of the previous flip-flop

by two, consequently the HEF4521B will count up to

224 = 16777216. The counting advances on the HIGH to

LOW transition of the clock (I2). The outputs of the last

seven stages are available for additional flexibility.

Fig.1 Functional diagram.

FAMILY DATA, IDD LIMITS category MSI

See Family Specifications

January 1995

2

Share Link: