Quad NOR gate with Schmitt-trigger inputs — why it matters for noisy rails
The SN74HC7002D: The Schmitt-trigger hysteresis cleans up slow edges from RC debounce networks, long PCB traces, or sensors with rise times that would otherwise cause the gate to oscillate or draw shoot-through current.
At 5 V the low-level threshold is 0.3 V to 1.2 V; the high-level threshold is 1.5 V to 4.2 V, so a 3.3 V CMOS output driving a 5 V-powered gate still meets the high-level minimum. Output drive is 5.2 mA per channel in both sink and source — enough for a single LED, a relay coil via a transistor, or a short unterminated trace, but not for a 50 Ω backplane. The 2 µA quiescent current means it adds negligible draw in a battery-powered system.
22 ns propagation delay — timing closure for glue logic
Maximum propagation delay is 22 ns at 6 V with a 50 pF load.
Package and temperature grade — board-fit details
The SN74HC7002D comes in a 14-pin SOIC package (body width 3.90 mm), surface-mount only.