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TPS65381A-Q1: Can this device work with 5V input supply?

John11513
Expert 5720 points
Part Number: TPS65381A-Q1

Hi team,

My customer want to use TPS65381A-Q1 to power TMS570, however their system can only provide 5V supply. I wondered can this PMIC operated with 5V input? Is there any reference design for 5V operation?

Thank you,

John

  • 0
    TI__Genius 10885 points

    Hi John,

    VDD5 would be in dropout mode, but the PMIC might remain operational. Looping in the product expert to comment.

    Best Regards,

    Rick S.

  • 0 in reply to Richard Solarski
    TI__Mastermind 20590 points

    Hi John,

     

    If the only supply voltage available is 5V the TPS65381A-Q1 could not be used directly, because at least 5.8V supply is needed initially to power up (wake up) device. Once the device has started, it can operate with a supply down to 4.5V, but any regulator that is configured for 5V being in drop out as Rick pointed out. I assume for a TMS570 the VDD3/5 (normally used for MCU IO) would be configured for 3.3V so that would leave only the VDD5 (normally used for CAN or other 5V peripherals) in drop out unless the configurable/adjustable sensor supply output (VSOUT1) was also targeting 5V output.

     

    One simple way around this would be to run the device in open loop mode bypassing the integrated buck pre-regulator. You could use the 5V to supply the VDD6 pin which is the input to the integrated downstream regulators on the PMIC. A low current charge pump or boost circuit would have to boost the VBATP and VBAT_SAFING voltages above 5.8V to start the device. The VDD6_UV flag would be set continuously because the 5V supply input to VDD6 would be detected as UV.