TI TCA9548ARGERQ1

The TCA9548A-Q1 device features eight bidirectional translation switches controllable via the I2C bus. The SCL/SDA upstream pair expands to eight downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected based on the contents of a programmable control register. These downstream channels can be used to resolve I2C target address conflicts. For example, if an application requires eight identical digital temperature sensors, one sensor can be connected to each channel (0–7).

When a timeout or other improper operation occurs, the system controller can reset the TCA9548A-Q1 by asserting the RESET input low. Similarly, a power-on reset deselects all channels and initializes the I2C/SMBus state machine. Asserting RESET active also performs a reset and initialization without requiring the device to be powered down. This allows recovery when one of the downstream I2C buses is stuck in a low state.

Because the switches have pass-gate transistors, the VCC pin can be used to limit the maximum high voltage passed by the TCA9548A-Q1. By limiting the maximum high voltage, different bus voltages can be used on each pair, allowing 1.8V, 2.5V, or 3.3V devices to communicate with 5V devices without any additional protection. For each channel, an external pull-up resistor pulls the bus voltage up to the desired voltage level. All I/O pins are 5V tolerant.

• AEC-Q100 (Grade 1): compliant with automotive application requirements
• Functional Safety documentation available to support functional safety system design
• 1 to 8 bidirectional translation switches
• Compatible with I2C bus and SMBus
• Active-low reset input
• Three address pins supporting up to eight TCA9548A-Q1 devices on the I2C bus
• Channel selection via I2C bus in any combination
• All switch channels deselected at power-up
• Low RON switches
• Voltage level translation between 1.8V, 2.5V, 3.3V, and 5V buses
• Power-up glitch-free
• Hot insertion capable
• Low quiescent current
• Operating supply voltage range: 1.65V to 5.25V
• 5V tolerant inputs
• Clock frequency: 0 to 400kHz
• Latch-up performance exceeds 100mA per JESD 78 Class II

• Infotainment systems
• Body and control
• Routers (telecom switching equipment)
• Factory automation
• Products with I2C target address conflicts (e.g., multiple identical temperature sensors)