What this 74AHCT multiplexer does on the board
The SN74AHCT158PW is a single 4 x 2:1 multiplexer from the 74AHCT family. It selects one of two 4-bit input buses onto a single 4-bit output bus based on a common select line.
Lifecycle and sourcing reality
The SN74AHCT158PW is listed as Active with ROHS3 compliance. The 74AHCT family is a mature logic series with broad distribution — this part is not exotic.
