Dual 4-input AND gate in a breadboard-friendly DIP
The SN74AS21N: It runs on a 5V supply (4.5V to 5.5V) and delivers a propagation delay of 6ns at 5V with a 50pF load — fast enough for most glue-logic and gating tasks in TTL systems.
6 ns propagation delay — what it buys you
The 6 ns max delay at 5V and 50 pF is the headline number. In the 74AS family, that speed comes from Schottky-clamped transistors that avoid saturation delay. For a BOM decision: this part keeps up with fast bus handshakes and clock gating where a 74LS or 74HC gate would add a noticeable pipeline bubble. The trade-off is higher supply current than CMOS families — plan the 5V rail budget accordingly.
Not suited for automotive under-hood or outdoor telecom cabinets where the ambient can dip below freezing. If your application lives on a lab bench or inside a conditioned rack, this temperature grade is fine.
Through-hole DIP — hand-solder friendly
The 14-DIP (0.300", 7.62mm) package with through-hole mounting is about as breadboard-friendly as logic gates get. No hot-air, no paste stencil — just a soldering iron and a clean tip. For a repair tech swapping a failed gate on a legacy PCB, or a maker wiring up a 5V TTL project on a breadboard, this is the package you want. The supplier device package is 14-PDIP.