74HC251D,653 (NEXPERIA)

The 74HC251D is a 8-bit Multiplexer with eight binary inputs (I0 to I7), three select inputs (S0 to S2) and an OE. The select inputs select one of the eight binary inputs and route it to the complementary outputs (Y and Y). A high on OE causes the outputs to assume a high-impedance OFF-state. Inputs include clamp diodes that enable the use of current limiting resistors to interface inputs to voltages in excess of VCC.