These monolithic data selectors/multiplexers contain full on-chip binary decoding to select the desired data source. The SN74151AN selects one-of eight data sources. It has a strobe input which must be at a low logic level to enable the device. A high level at the strobe forces the W output high, and the Y output (as applicable) low.
The SN74151AN incorporates address buffers that have symmetrical propagation delay times through the complementary paths. This reduces the possibility of transients occurring at the outputs due to changes made at the select inputs, even when the outputs are enabled (i.e., strobe low). 16 pin DIP. Manufactured by Texas Instruments.