4 x 2:1 multiplexer in 16-SOIC
The CD74HCT257M96: It selects one of two 4-bit data inputs per channel under control of a common select line, with the output presenting the selected data in true (non-inverted) form. The output sink and source capability is rated at 6 mA each, sufficient for driving downstream logic inputs or low-power LEDs with a series resistor.
The 16-SOIC body (3.90 mm width) fits standard SOIC-16 footprints; the 1.27 mm pitch is compatible with 2-layer PCB routing without via fan-out. The single-supply architecture simplifies power distribution — no negative rail needed. The 74HCT family's input thresholds are TTL-compatible, so this multiplexer interfaces directly with 5 V TTL logic without external level translation.