Low-power XNOR with Schmitt-trigger inputs
The SN74AUP1T87DCKR is a single 2-input XNOR gate from TI's 74AUP low-power logic family, featuring Schmitt-trigger inputs for noise immunity on slow or noisy signal edges.
Signal integrity and timing for the BOM
The Schmitt-trigger inputs accept slow-rising signals from sensors or RC oscillators without chatter — the low-level threshold is 0.35 V to 0.5 V, and the high-level threshold is 1.1 V to 1.19 V, providing hysteresis that rejects noise on long PCB traces. Maximum propagation delay is 4.4 ns at 3.3 V with a 30 pF load, which sets the timing budget for the downstream flop or counter in a mixed-voltage interface. The output can source or sink 4 mA, adequate for driving a single CMOS load or a low-current LED indicator directly.