7491 – 8-bit serial shift register, TTL, DIP-14 (generic)

The 7491 is a classic standard TTL IC containing an 8-bit serial-in, serial-out shift register. Data enters through a gated input (two inputs A and B, ANDed) and moves one stage on each rising clock edge; the last stage is available on complementary outputs (Q and /Q). It is used, for example, as a delay line or serial buffer. Note the pinout with the supply on pin 5 and ground on pin 10. The LS version is the 74LS91. It runs from a 5 V supply. It comes in a 14-pin plastic DIP.

Condition: mixed surplus lot, untested. The bag may contain used (pulled) ICs of the same type from different manufacturers, so marking and date code vary. The photo shows one chip from this lot (7491N 7812); only the background was cleaned to white, preserving the marking and leads.

Minimum order: 1 pc.