TCA9546APWR

The TCA9546A is a quad bidirectional translating switch controlled via the I²C bus. The serial clock/serial data (SCL/SDA) upstream pair fans out to four downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected based on the contents of the programmable control register. An active-low (RESET) input allows the TCA9546A to recover when one of the downstream I²C buses is stuck in a low state. Pulling RESET low resets the I²C state machine and deselects all channels, functioning identically to the internal power-on reset. The switches incorporate pass-gate circuitry so that the VCC terminal pin can be used to limit the maximum high voltage passed by the TCA9546A. This allows different bus voltages on each pair, enabling 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 to the required level. All I/O pins are 5.5V tolerant.

Applications

• Servers
• Routers (telecom switching equipment)
• Factory automation
• Products with I²C slave address conflicts (multiple identical temperature sensors)

Key features

• 4-channel bidirectional switching with I²C bus and SMBus compatibility
• Active-low reset input
• Three address pins supporting up to eight TCA9546A devices on the I²C bus
• Any combination of channel selection via I²C bus
• All switch channels deselected at power-up
• Low RON switches
• Voltage level translation between 1.8V, 2.5V, 3.3V, and 5V buses
• No glitch at power-up
• Hot insertion support
• Low standby current
• Operating supply voltage range: 1.65V to 5.5V
• 5.5V tolerant inputs
• Clock frequency: 0 to 400kHz
• Latch-up performance exceeds 100mA per JESD78
• ESD protection exceeds JESD22 requirements
• 4000V Human Body Model (A114-A)
• 1500V Charged Device Model (C101)