74157 IC

The 74157 is a quad 2-line to 1-line multiplexer. Basically how this works is there are two inputs ( A and B ) for every output ( Y ). There are four groups like this, with two inputs and one output each. There is one select signal for the whole chip. When the select signal is low, the output ( Y ) is the same as input A. When the select signal is high, the output Y is the same as input B.

IC 1
Pin Function Function Pin
1 Select Vcc 16
2 1A CE 15
3 1B 4A 14
4 1Y 4B 13
5 2A 4Y 12
6 2B 3A 11
7 2Y 3B 10
8 Gnd 3Y 9

Uses