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TPS7A25: Internal feedback resistor tolerances

Nicholas Haneline
Prodigy 10 points
Part Number: TPS7A25

I have a quick question regarding the internal feedback resistors on the fixed output versions of the TPS7A25. 

  • For a 5V output what are the resistor values, power ratings, and tolerances.

Best Regards, 

Nick Haneline

  • 0
    TI__Genius 12511 points

    Hi Nick,

    Edgar will get to you promptly, thank you for your patience

  • 0
    TI__Genius 12365 points

    Hi Nick, 

    Thank you for reaching out to us. 

    I'm still waiting on a response from our Design Team, however, the internal R1 and R2 tend to have a +-20% tolerance. 

    Can you share with us the use case of this information? Thank you

    Best, 

    Edgar Acosta

  • 0 in reply to Edgar Acosta1
    Prodigy 10 points

    Hi Edgar, 

    Thank you for the clarification on the internal resistor tolerances. As for the use case, I'm doing a Monte Carlo simulation on the setpoint of this device for use as a 5V bias supply to another LDO. 

  • 0 in reply to Nicholas Haneline
    TI__Mastermind 33345 points

    Hi Nick,

    There is no need to conduct a monte carlo simulation on TI devices where the feedback network is internal to the die.  We have the total accuracy information listed in the datasheet across DC conditions - see the snapshot below.  For this device the output voltage is +/- 1% maximum, and this tolerance is at production quantities so actual performance is typically better.  Any tolerance of the internal resistors (such as 20%) is likely initial and most definitely NOT the final tolerance as many / most LDO's are now trimmed.  You are not going to purchase and receive an LDO from TI with tolerance anywhere NEAR 20%, it will be 1% or better.

    Thanks,

    Stephen

  • 0 in reply to Stephen Ziel
    Prodigy 10 points

    Hi Stephen,

    I knew 20% was probably not right, so I used 1%. The main reason I was asking for the tolerance values was to make sure my simulations are as accurate as possible. In any case, thank you for the timely response. I appreciate it.

  • +1 in reply to Stephen Ziel
    TI__Genius 12365 points

    Hi Nicholas, 

    In addition to Stephen's response.

    Design team responded and the bottom resistor is 12Mohm, and the maximum current that is allowed should be 5uA. Anything beyond this will damage the internals. 

    I will also correct myself with the tolerance, they did not provide a number, but this should be way tighter, and as Stephen explained the 20% should be an initial but not the final value. 

    Best, 

    Edgar Acosta

  • +1 in reply to Edgar Acosta1
    Prodigy 10 points

    Got it. Thanks for the clarification and resistor values.