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TPS74801: Vref and output accuracy over temperatuer

Kevin Wen
Intellectual 2235 points
Part Number: TPS74801

Hi team,

The TPS748 datasheet indicate the device output accuracy is 2% over -40~125degC temperature range, as this near to the design limit of customer's application, they need your to understand the how the accuracy change versus temperature, would you please suggest if you can provide some test result or some figure to explain this? thanks. 

Kevin

  • 0
    TI__Guru 50040 points

    HI Kevin,

    The VREF internal accuracy is the best to look at as it ignores the effects if input voltage change and load current change. I looked at that test data for the device and while the datasheet correct states that this is tested at 25C, The VREF in fact meets the datasheet limits from -40 to 125C:

    Note: this is the reference accuracy only, it does not consider the external resistors.

    Does this answer your question?

  • 0 in reply to JCHK
    TI__Intellectual 2235 points

    Hi JCHK,

    thanks for your reply, we wish to further understand the relationship between output voltage vs temperature. is it linear relationship? is it negative temperature coefficient or positive temperature  coefficient? thanks. 

    Kevin

  • 0 in reply to Kevin Wen
    TI__Mastermind 23361 points

    Hi Kevin, 

    For LDO, the output voltage is a gain of the internal reference voltage. The reference is normally trimmed at 25C, and as bandgap is one of the most commonly used way to create a reference, the curves should be generally flat as the idea of band gap reference is to use a negative temperature coefficient term to cancel out the positive term.

    Regards,
    Jason