The Texas Instruments TCA9548ARGERQ1 is a 1 x 8:1 bus switch, essentially an I2C/SMBus multiplexer that lets one master talk to up to eight downstream buses, each selected via the control register. It carries AEC-Q100 automotive qualification, so it's specced for the temperature swings and reliability demands of automotive electronics, but it's equally at home in any industrial or high-reliability system that needs to isolate or expand an I2C bus.
The supply range runs from 1.65V to 5.25V, single-supply only. That covers 1.8V, 2.5V, 3.3V, and 5V logic rails without needing a level shifter on the supply pin — just match the bus voltage of the master.
Package and footprint — what the assembly line needs to know
It comes in a 24-VFQFN with exposed pad, 4x4 mm body. That exposed pad is the thermal and electrical ground connection — the datasheet layout shows a central via pattern under the pad. The part is surface-mount only, and the package code is 24-VQFN (4x4).
The base product number is TCA9548, so if you see a different suffix (e.g. TCA9548APWR), that's a different package variant — check the package code before substituting.