●1-to-8 Bidirectional translating switches ●I²C Bus and SMBus compatible ●Active-low reset input ●Three address pins, allowing up to eight TCA9548A devices on the I²C bus ●Channel selection through an I²C Bus, in any combination ●Power up with all switch channels deselected ●Low R_ON switches ●Allows voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses ●No glitch on power up ●Supports hot insertion ●Low standby current ●Operating power-supply voltage range of ●1.65 V to 5.5 V ●5-V Tolerant inputs ●0- to 400-kHz Clock frequency ●Latch-up performance exceeds 100 mA Per JESD 78, class II ●ESD Protection exceeds JESD 22

○±2000-V Human-body model (A114-A) ○200-V Machine model (A115-A) ○±1000-V Charged-device model (C101)

The TCA9548A device has eight bidirectional translating switches that can be controlledthrough the I²C bus. The SCL/SDA upstream pair fans out to eightdownstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can beselected, determined by the contents of the programmable control register. These downstreamchannels can be used to resolve I²C slave address conflicts. Forexample, if eight identical digital temperature sensors are needed in the application, one sensorcan be connected at each channel: 0-7.

The system master can reset the TCA9548A in the event of a time-out or other improperoperation by asserting a low in the RESET input. Similarly, the power-onreset deselects all channels and initializes the I²C/SMBus statemachine. Asserting RESET causes the same reset and initialization to occurwithout powering down the part. This allows recovery should one of the downstreamI²C buses get stuck in a low state.

The pass gates of the switches are constructed so that the VCC pin can be used to limitthe maximum high voltage, which is passed by the TCA9548A. Limiting the maximum high voltage allowsthe use of different bus voltages on each pair, so that 1.8-V, 2.5-V or 3.3-V parts can communicatewith 5-V parts, without any additional protection. External pullup resistors pull the bus up to thedesired voltage level for each channel. All I/O pins are 5-V tolerant.