Why the 4.5 ns propagation delay matters for your timing budget
The SN74AS00N is a quad 2-input NAND gate from the 74AS family, delivering a 4.5 ns max propagation delay at 5V and 50 pF load — roughly half the delay of a 74LS00, which means the AS part can close timing in a 5V TTL bus where the LS part leaves no margin. Each of the four gates sinks 20 mA and sources 2 mA, so a single output can drive up to ten standard LS loads (fan-out of 10) before the voltage drop at the source side becomes a concern.
Supply rail and input thresholds — direct 5V TTL fit
The supply range is 4.5V to 5.5V, matching the legacy 5V TTL rail. Input low threshold is 0.8V max, input high is 2V min — so the gate switches cleanly on standard TTL levels without needing a level translator. Compared to the SN74F00DR (5 ns delay, same supply and threshold levels), the AS00N is 0.5 ns faster but comes only in a through-hole DIP — the F00DR is surface-mount SOIC, which changes the board assembly process.
ROHS3 compliant.