PHILIPS 74F139 handbook
Datasheet
This document describes the product specifications of the 74F139 Dual 1-of-4 decoder/demultiplexer. The device has two independent decoders, each accepting two binary weighted inputs and providing four mutually exclusive active-Low outputs. Each decoder has an active-Low Enable pin, which, when high, forces all outputs to be high. The device has multifunction capability.