74HCT191DB中文资料飞利浦数据手册PDF规格书

GENERAL DESCRIPTION

The 74HC/HCT191 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.

The 74HC/HCT191 are asynchronously presettable 4-bit binary up/down counters. They contain four master/slave flip-flops with internal gating and steering logic to provide asynchronous preset and synchronous count-up and count-down operation.

FEATURES

• Synchronous reversible counting

• Asynchronous parallel load

• Count enable control for synchronous expansion

• Single up/down control input

• Output capability: standard

• ICC category: MSI