• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 148 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS7A33: CNR/SS Value

Mitchell
Expert 4915 points
Part Number: TPS7A33

Hi Team,

My customer and I have some confusion around the recommended value for NR/SS (pin 2) on the TPS7A33. On page 4, the datasheet suggests using 1uF for CNR/SS. This seems incredibly high and based on equation 1 in section 7.3.3 will result in a 1.2s soft start.

Also, most charts in the datasheet show a 10nF or 100nF value for CNR/SS. Due to the inconsistencies, we are a little confused what value to use. 

If the customer wants to use 10nF instead of 1uF to achieve quicker start up, will this have any impact on device performance?

Thanks,
Mitchell

  • +1
    TI__Mastermind 23361 points

    Hi Mitchell, 

    Using 10nF is perfectly fine. A bigger capacitor at the Cnr/ss will filter more noise but it will result in a much longer startup time. The datasheet has noise performance with Cnr/ss = 10nF and if this is good enough for the application, you don't have to go higher than 10nF. 

    Regards, 
    Jason Song