8-bit identity comparator for board-level match detection
The CD74HC688E is an 8-bit identity comparator from the 74HC series. It compares two 8-bit words and asserts the output low when they match.
Max propagation delay is 29 ns at 6V with a 50 pF load. Quiescent current is 8 µA.
Through-hole DIP package — legacy board fit
The 20-pin DIP package (0.300" body, 7.62 mm pitch) is a through-hole footprint common in industrial control cards, prototyping boards, and retrofit repairs. It sits in a 20-PDIP socket or solders directly into plated through-holes.