• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 66 subscribers
  • Views 493 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LM26480: Please help with understanding buck input capacitor requirements

Stan Stepnowski1
Prodigy 20 points

Part Number: LM26480

Hello,

I have a question about the input capacitor requirements for the buck regulators of the LM26480.  The minimum capacitance is 10uF as given in section 7.7 of the datasheet.  

The application circuit in Figure 26 uses 10uF capacitors on VIN1 and VIN2 for the bucks, and the LM26480SQ-AAEV eval board uses these, too.

Other buck regulators we have used, like the LMR33630B, recommend a smaller <1uF cap (100nF or 220nF in this case) for high frequency bypass in addition to a larger bulk capacitance.

Could you please tell us why the LM26480 doesn't require these smaller caps on VIN1, VIN2 or any of the other supply pins?

Thank you very much for your help!

Best regards,

Stan

  • +1
    TI__Genius 12735 points

    Hi Stan,

    With any switching regulator using small value capacitors (<1uF) can help with ripple both on the input and output. Using these capacitors with LM26480 should not be an issue and I would recommend doing so in a design.

    Best regards,

    Layne J