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LMR14050-Q1: FB pin leakage?

Ed Walker1
Prodigy 20 points
Part Number: LMR14050-Q1

The data sheet doesn't specify a leakage value for the feedback pin. However 7.3.5 says, "However, if the [feedback resistor] values are too high, the regulator will be more susceptible to noise and voltage errors from the FB input current may become noticeable."  So what is the leakage, and does it vary by temperature?
Thanks

  • 0
    TI__Expert 3480 points

    Hi Ed,

       We don't write the leakage data in the datasheet.   If you design the feedback following the datasheet, it will not hit leakage limit. 

    Gavin

  • 0 in reply to Gavin Wang (Zejing)
    Prodigy 20 points

    Thank you Gavin. I know the data sheet doesn't list FB pin leakage. But the data sheet also says it can have an effect. What is the effect?; i.e what is the leakage, and does it vary by temperature? If you don't know this, do you have any measured data? Can you describe the FB pin input structure, so that an estimate of leakage can be made? Thanks.

  • 0 in reply to Ed Walker1
    TI__Mastermind 25590 points

    Ed,

    The FB pin will have a current between -5nA and 5nA from -40C to 125C. So I don't expect this current to affect the output voltage regulation point unless the feedback resistors are in the tens or hundreds of megaohms. You're asking about the automotive version so your design will probably only go as high as 100kohms.

    -Sam