Dual 1-of-4 decoder in a through-hole DIP
The CD74AC139E is a dual 1-of-4 decoder/demultiplexer from TI's 74AC family, packing two independent 2:4 circuits into a single 16-pin DIP. Each section takes a 2-bit binary address and pulls one of four outputs low — the classic 74AC139 function, but in the wide-body 0.300-inch DIP that breadboards and through-hole prototypes still need.
Each output sources or sinks 24 mA — enough to drive a standard LED directly or fan out to four LSTTL loads per pin.
Package and rework — 16-pin DIP, hand-solder friendly
Housed in a 16-lead PDIP (0.300-inch body, 7.62 mm wide), the CD74AC139E is about as rework-friendly as logic gets. The 0.100-inch pin pitch and through-hole leads survive repeated soldering iron cycles — lift the part, not the pad, and it goes back in clean. No moisture sensitivity level to track; no bake-out required before assembly.
