@A M Bhatt, Can u then suggest a way to power only one of the four devices at a time, so that when I give 00 on the input, device 1 must be powered, 01, device 2 must be powered and so on…The devices in question are RF link transmitters and receivers ( 433Tx, 433Rx, 315Tx, 315Rx ). At a given point of time i need to power only one of the modules. They dont have EN, etc pins. Please forgive me for my ambuigity in the earlier post.