• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 34 subscribers
  • Views 542 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.

12A Buck

Adam Mc Gaffin
Mastermind 30000 points

Other Parts Discussed in Thread: TPS65981EVM, LM3489, LM25085

Hi Team,

Reaching out to see if y'all have any recommendations for a part based on our criteria. We need a buck with a duty cycle of 100% and a current out max of around 12A.

  • 0
    TI__Guru**** 191445 points
    Adam,
    You did not mention your required output voltage and input voltage range. Di you need pure 100% duty cycle? Most buck converters with n-FET will have a BOOT circuit to provide the gate drive. Duty cycle can extend beyond 100% but the high side switch must turn off periodically to allow the BOOT capacitor to recharge. Is this action acceptable?
  • 0 in reply to JohnTucker
    TI__Mastermind 30000 points
    Hey John,

    Thanks for the response. We are currently using the LM3489, which is hysteretic p-fet buck controller. You can see the use case in the TPS65981EVM. We need the 100% duty cycle so we can pass the 20V barrel jack power to the Type-C port with minimal loss. However, for our next we are trying to source 10A from one supply. On the LM3489 we are controlling the feed back loop via GPIO's to adjust the output voltage to 5V, 9V, 15V, and 20V from the 20V barrel jack source. We are looking for something similar to the LM3489 that can handle 12A of output current. Do you have any recommendations based on these criteria?
  • 0 in reply to Adam Mc Gaffin
    TI__Guru**** 191445 points

    Adam,

    Take a look at LM25085:

    Let me know if that will work for you.

  • 0 in reply to JohnTucker
    TI__Mastermind 30000 points
    John
    Took a look through the datasheet and I think this will work for us. We ordered an EVM to test out the part ourselves to see if it's a good fit. Thanks for your help.