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TRS3232E-Q1: Isolated communication

Part Number: TRS3232E-Q1
Other Parts Discussed in Thread: TIDA-01094, TRS3232E, MAX3232, TRS3232


in my application, an embedded electronic is communicating via a RS232 interface with a host PC. Currently, I'm using the TRS3232EQPWRQ1.

In some of your reference designs (e. g. TIDA-01094), I saw that you use an isolated RS232 communication. In TIDA-01094, you use the ISO7321.

There is no isolator in my design up to now. I just connected the UART port of my microcontroller directly to the TRS3232E.

When do you recommend to use this isolator?

Would I also need the isolator, if I would use the MAX3232MPWREP?

  • Lehmann,

    The isolation is needed if the ground of your RS232 transmitter and receiver has big shift, for example around ±10V for TRS3232E. TIDA-01094 gives a good example of isolated communication by measuring isolated shunt current. You can make your call if it has same requirement in your application. Please let us know if you have more questions.




  • Hello,

    so I understand that I need the isolation if I have e. g. two independent power supplies for receiver and transmitter.

    Would I also need the isolator if I would use the MAX3232MPWREP?



  • Stefan,

    It would be same story. MAX3232 and TRS3232 have many similar electrical characteristics. Please let me know if you have any questions.