DM74LS20 Description
This device contains two independent gates each of which performs the logic NAND function. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table Y = ABCD Inputs A X X X L H B X X L X H C X L X X H D L X X X H Output Y H H H H L H = HIGH Logic Level L = LOW Logic Level X = Either LOW or HIGH Logic Level © 2000 Fairchild Semiconductor Corporation DS006355 .fairchildsemi.