• TI Thinks Resolved

TPS3895: Sense_out to be low before VPOR

Part Number: TPS3895

Dear Team,

TPS3895 SENSE_OUT status is unknown during power on before VPOR and is shown in below highlighted area. 

A 10k-ohm pull low resistor is used but during power on there is still a spike on SENSE_OUT.

May I know if there is any way to make sense_out low during power on?

Thank you.

Regards,

Ting

  • Ting,

    We have a solution to keep the SENSE_OUT low until the VCC comes up then the device works as normal (SENSE_OUT will be just slightly lower than normal when "high"). It requires 2 external MOSFETS and 2 external resistors at the output. Q1 is N-FET and Q2 is P-FET. See solution below.

    Will this solution work for you?

    -Michael

  • In reply to Michael DeSando1:

    Hello Michael,

    May I know if there is experimental data like test waveform and suggested TI mosfet?
    We are applying EVM to do test. But if there is test data, that will be a big help for us.

    Thank you!
    Regards,
    Ting
  • In reply to Ting Ye:

    Ting,

    We have ran some simulations and we believe this solution is valid. See the schematic and results below. Note: I have the SENSE_OUT pulled low until Vcc reaches ~1.5V which should be fine since the minimum recommended operating voltage is 1.7V.

    Results:

    Some bench testing is still needed but I have some parts to aim for now.

    -Michael