74AHC139

The 74AHC139 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 74AHC139 are high-speed, dual 2-to-4 line decoder/demultiplexers.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  139 is identical to the HEF4556 of the HE400B family.