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TPS74901: Vout accuracy below 50mA load current

Jason Dai
Expert 3720 points
Part Number: TPS74901

Hello E2E,

What is Vout accuracy while loading below 50mA?

or

TPS74901 require minimum load is 50mA for stability?

BR,

Jason 

  • 0
    TI__Mastermind 43610 points

    Hi Jason,

    Because the TPS749 has a very large pass FET to support the 3A of load current, at very light loads we have a circuit to weakly pull-down VOUT to prevent leakage from VIN to VOUT from raising VIN above its target regulation voltage.  My recollection is that the threshold for this mode change is in the 10-20mA range. If you sweep the load current slowly, you would see a small step change in the output voltage.  This is the reason we specify accuracy starting from 50mA. 

    There is no minimum load current requirement as stated in the recommended operating table:

    I hope this answers your question.

  • 0 in reply to JCHK
    TI__Expert 3720 points

    John,

    thanks for your replied.

    Customer still wants to know what is the accuracy as worst case while loading is below 50mA?

    BR,

    Jason

  • 0 in reply to Jason Dai
    TI__Mastermind 43610 points

    Hi Jason,

    We don't have the accuracy data below 50mA. Are they looking for a lower current regulator?

    Regards,

  • 0 in reply to JCHK
    TI__Expert 3720 points

    John,

    customer already design tps74901 on system whose loading may be possible lower than 50mA.

    could you please help to get the accuracy data at lower 50mA loading?

    BR,

    Jason

  • 0 in reply to Jason Dai
    TI__Mastermind 43610 points

    Hi Jason,

    I have been asking for this but our apps team is swamped with end of year support activities. My recollection is that if you put a minimuim 20mA load or more, the accuracy will match the PDS. 

    Regards,