Open-collector NAND for load-driving and wired-OR
The TI SN74S38NS is a quad 2-input NAND gate from the 74S Schottky TTL family, built with open-collector outputs. That open-collector stage is the key feature: each output can sink up to 60 mA — enough to drive a small relay coil, an optocoupler LED, or a panel indicator without an external transistor. It also lets you wire multiple gate outputs together to form a wired-OR connection, useful for shared interrupt or status lines on a backplane. Supply voltage is a tight 4.75 V to 5.25 V, standard for 5 V TTL logic. The 9 ns propagation delay at 5 V with a 150 pF load keeps up with most board-level glue logic but won't stretch to high-speed clock trees. Operating temperature is 0°C to 70°C — commercial grade, so this is an indoor, controlled-environment part.
Lifecycle and sourcing
The SN74S38NS carries an Active product status and is ROHS3 compliant. For a BOM line that needs a 5 V open-collector NAND, this part is a straightforward fit — no end-of-life risk to plan around.