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TPS74801: Iss current upper and lower spec

Part Number: TPS74801


Could you please provide the max and min value of Iss, customer is using 3300pF as soft start Cap design but the test result slew rate is not accuracy, we need the max and min value to evaluation.

  • Hi Jim,

    Here is the characterization data for ISS for the DRC package. The RGW package characterization data is similar but slightly different. 

    -40C 25C 125C
    Mean 464.16 467.56 466.85
    Sigma 4.752 4.4954 3.659



  • Hi Nick,

    Do we have min spec for the current?

    Customer is using 3300pF and the calculation SS time should be 6ms, but we measured SS time only 4.27ms as below.

  • Hi Jim,

    A minimum spec can be calculated from the information I provided. For example, the minimum 6-sigma of these 3 distributions is at -40C, where the minimum is 435.6nA. For this I think the maximum current is more relevant, and I calculate the maximum 6-sigma of these distributions to be at 25C with 488.8nA. 

    Can they use the cursors on the oscilloscope to calculate the ISS current? Also remember that the capacitor has a pretty high tolerance as well. 

    One other consideration is that the datasheet isn't clear how the soft-start startup time is measured. They have used what looks like a 10%-90% rise time, whereas the datasheet might be referring to a total ramp time.