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. 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.