1. General description

The 74AHC139; 74AHCT139 is a high-speed Si-gate CMOS device and is pin compatible

with Low-power Schottky TTL (LSTTL). It is specified in compliance with JEDEC standard

No. 7-A.

The 74AHC139; 74AHCT139 is a high-speed, dual 2-to-4 line decoder/demultiplexer. This

device has two independent decoders, each accepting two binary weighted inputs (nA0

and nA1) and providing four mutually exclusive active LOW outputs (nY0 to nY3). Each

decoder has an active LOW enable input (nE). When nE is HIGH, every output is forced

HIGH. The enable input can be used as the data input for a 1-to-4 demultiplexer

application.

The 74AHC139; 74AHCT139 is identical to the HEF4556 of the HE4000B family.

2. Features

n Balanced propagation delays

n All inputs have Schmitt-trigger actions

n Inputs accept voltages higher than VCC

n Input levels:

u For 74AHC139: CMOS level

u For 74AHCT139: TTL level

n ESD protection:

u HBM EIA/JESD22-A114E exceeds 2000 V

u MM EIA/JESD22-A115-A exceeds 200 V

u CDM EIA/JESD22-C101C exceeds 1000 V

n Multiple package options

n Specified from -40 °C to +85 °C and from -40 °C to +125 °C

74AHCT139D属于集成电路（IC） > 信号开关，多路复用器，解码器。安世半导体(中国)有限公司制造生产的74AHCT139D信号开关，多路复用器，解码器逻辑型信号开关、多路复用器和编码器 IC 可用于对以数字格式表示数据的电信号进行路由和选择。这些器件与设计用于模拟信号的类似产品有所不同，它们保留的信息表示为两个电状态之一，而不是两个外部界限内的无穷变化量。