Part Number: TCA9548A
Other Parts Discussed in Thread: TXS0102,
Dear all,
I'm developing a design which interconnects two separate boards via i2c.
- The Slave board receives 5V and has a 1.8V LDO to power the logic. To limit the size, the wire connector only has 4 pins (5V, gnd, sda scl).
- The Master board has a 3.3V microcontroller and a 5V power supplied to the Slave board.
The Master has a TCA9548A multiplexer that receives from a number of Slaves.
At the moment, I would like to translate the voltage onboard the slave and send back a 5V i2c signal using the TXS0102. Would I need pullup resistors between the 2? I'm aware I don't usually need them for the TXS0102 but I'd like a confirmation (400KHz max) of interoperation between the two. Once the signal has reached the Master, the microcontroller side of the multiplexer will pull-up at 3.3V (here I need resistors).
I'm doing this weird translation because I imagine there might be a current/voltage loop problem if I put a dedicated 1.8V LDO/reference source on the Master board for the TCA9548A.
Let me know what you think.
