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TCAN1044A-Q1: TXD & RXD 3.3V

Brian Li
Genius 13850 points
Part Number: TCAN1044A-Q1

Hi team，

My customer is using our TCAN1044ADRQ1, the voltage from MCU is 3.3V.

Since our TCAN1044ADRQ1 don't have VIO pin, in theory the voltage on TXD & RXD should be 5V，but they didn't find any abnormal with 3.3V.

They tested TXD and RXD as below, could you please kindly help check if there's any risk with this 3.3V?

Thanks,

Brian

  • 0
    Guru 316780 points

    VIH is specified as 0.7 × VCC = 3.5 V. So even if it happens to work in the lab, it is not guaranteed to work in all circumstances.

  • +1 in reply to Clemens Ladisch
    TI__Guru 74252 points

    Brian,

    As Clemens said, in a lot of cases it will work, but the cases where your VCC voltage could change between 4.5 to 5.5V, the temperature is very cold (-40C or closer), there could be issues where the high level isn't recognized by the transceiver. It's better to use a V version of the device unless the application can guarantee the VCC voltage and temperature range to be nominal conditions. Even then though, it is not recommended to use a 5V transceiver without VIO pin in a 3.3V logic application.

    Regards,

    Eric Hackett