The Microchip SY89474UMG is a Precision Edge® 1 x 2:1 multiplexer in a 24-MLF® (4x4) package, built for a single supply rail between 2.375 V and 2.625 V. That tight 250 mV window means the 2.5 V rail must be within regulation — a 5% tolerance supply is fine, but a 3.3 V LDO feeding a 2.5 V post-regulator adds dropout margin to check.
1 x 2:1 — what the circuit count means for signal routing
A single independent 2:1 multiplexer selects between two input signals onto one output. The single-supply 2.5 V core limits the signal swing — this is a digital or small-swing analog multiplexer, not a rail-to-rail analog switch for ±5 V paths. The 24-MLF® package keeps the signal path short, which matters for high-frequency edge rates in clock or data distribution.