• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 279 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.

LM73605-Q1: Cboot selection

Given Ding
Genius 10465 points
Part Number: LM73605-Q1


Hi Team,

Just want to check if Cboot can be 0.1uf or 1uf since datasheet recommend 0.47uf. Thanks.

  • 0
    TI__Mastermind 25590 points
    Given,

    1uF will be fine. 0.1uF may not be fine. Here are the considerations:

    Decreasing capacitance (using 0.1uF instead of 0.47uF) means the capacitor holds less charge meaning it may discharge more as it tries to turn on the high-side FET. Dropping too much means the FET won't turn on as strongly causing more Rds_on loss and lower efficiency overall. If the boot voltage drops low enough then you will hit the boot UVLO and the part will stop working.

    Increasing capacitance is generally fine. The only consideration I can think of is that it may delay startup since it requires more time to charge. But this would be for very large values of Cboot coupled with very small soft start cap. I doubt 1uF will get close to this territory.

    -Sam