The TCA9846 is a quad bidirectional translating switch controlled via the I2C bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register.
An active-low reset ( RESET) input allows the TCA9846 to recover from a situation in which one of the downstream I2C buses is stuck in a low state. Pulling RESET low resets the I2C state machine and causes all the channels to be deselected, as does the internal power-on reset function.
The pass gates of the switches are constructed so that VDD1/VDD2 pins can be used to limit the maximum high voltage, which is passed by the TCA9846. Limiting the maximum high voltage allows the use of different bus voltages on each pair, so that 0.65V, 0.8V, 1.2V, or 1.8V parts can communicate with 3.3V parts, without any additional protection. External pullup resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 3.6V tolerant.
The TCA9846 is a quad bidirectional translating switch controlled via the I2C bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register.
An active-low reset ( RESET) input allows the TCA9846 to recover from a situation in which one of the downstream I2C buses is stuck in a low state. Pulling RESET low resets the I2C state machine and causes all the channels to be deselected, as does the internal power-on reset function.
The pass gates of the switches are constructed so that VDD1/VDD2 pins can be used to limit the maximum high voltage, which is passed by the TCA9846. Limiting the maximum high voltage allows the use of different bus voltages on each pair, so that 0.65V, 0.8V, 1.2V, or 1.8V parts can communicate with 3.3V parts, without any additional protection. External pullup resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 3.6V tolerant.