HEF4521B 查看數據表（PDF） - NXP Semiconductors.
零件编号
产品描述 (功能)
生产厂家
HEF4521B Datasheet PDF : 18 Pages
| |||
HEF4521B
24-stage frequency divider and oscillator
Rev. 6 — 21 November 2011
Product data sheet
1. General 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 (A2 to Y2) functions as: a crystal oscillator, an input buffer for an
external oscillator or in combination with A1 as an RC oscillator. The crystal oscillator
operates in Low-power mode when pins VSS1 and VDD1 are supplied via external resistors.
Each flip-flop divides the frequency of the previous flip-flop by two, consequently the
HEF4521B counts up to 224 = 16777216. The counting advances on the HIGH-to-LOW
transition of the clock (A2). The outputs from each of the last seven stages (218 to 224) are
available for additional flexibility.
It operates over a recommended VDD power supply range of 3 V to 15 V referenced to VSS
(usually ground). Unused inputs must be connected to VDD, VSS, or another input.
2. Features and benefits
Low power crystal oscillator operation
Fully static operation
5 V, 10 V, and 15 V parametric ratings
Standardized symmetrical output characteristics
Specified from 40 C to +85 C
Complies with JEDEC standard JESD 13-B
3. Ordering information
Table 1. Ordering information
All types operate from 40 C to +85 C.
Type number
Package
Name
Description
HEF4521BP
DIP16
plastic dual in-line package; 16-leads (300 mil)
HEF4521BT
SO16
plastic small outline package; 16 leads; body width 3.9 mm
Version
SOT38-4
SOT109-1
Share Link: 