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TPS79901-EP: feedback resister value

Andy_Lin
Intellectual 2580 points
Part Number: TPS79901-EP

Hi Team,

my customer is using TPS79901 as solution and have question regarding feedback resister value ,

they need precise IFB data(normal) to calculate right value of R1 and R2, per d/s specified , they only shows the max and min value .do we have this data to provide?

 

if yes , to get precise feedback value , normally we will estimate 50~100 times feedback current(Vout/R1+R2) higher than fb pin's sink current , is my understanding correct?

please kindly help suggest the comment for the above questions , thanks!  

Andy

  • 0
    TI__Mastermind 37005 points

    Hi Andy,

    The typical value is normally very low and therefore difficult to measure.
    The challenge in measuring it is likely why it is not listed here.
    In these cases you can use 0uA as the typical.

    For a rough first order estimate, yes you can use 50-100 times the feedback current in the method you described.

    You can also use a statistical analysis for a higher fidelity analysis.
    If you provide me the setpoint requirements (nominal, tolerance), I can run a statistical analysis on hundreds of setpoints within minutes and provide you the top 10 resistor combinations for your customer to choose.

    Thanks,

    - Stephen

  • 0 in reply to Stephen Ziel
    TI__Intellectual 2580 points

    Hi Stephen,

    thanks for the feedback,

    I'll provide the customer spec and setpoint if they request for the recommend FB resister value, thanks!

    Andy