• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 325 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.

TPS51285B: About TPS51285B OCL setting...

Peter Tseng
Genius 5660 points
Part Number: TPS51285B
Other Parts Discussed in Thread: CSD87350Q5D

Dear Sirs,

My customer is testing with TPS51285B and want to set up the OCL with attached excel tool.

However, with the result of tool, it seems the OCL value is very large than customer target.

The OCL result got from tool is 29.3A.

Can you help to check what's wrong with it?

Thanks.

Here are customer configuration.

1. 5V/12A output, OCL need to set as 15A

2. 3.3V/15A output, OCL need to set as 16A

3. MOSFET use CSD87350Q5D and TOP RDS 5mΩ，LOW RDS 1.2 mΩ

4. CHOKE is 1.5uH,3.7 mΩ

 

Tps51285_Design_support_sheet_r0.2.xlsx

  • 0
    TI__Expert 6425 points

    Hi Peter, 

    Because the low side Rdson of the Mosfet is too small. So it need a lower Vtrip voltage. so the Rcs is small. If the Rcs voltage is too small, it couldn't meet Vtrip voltage. The minimum Vtrip voltage is 0.2V. 

    solution 1: use a larger Rdson Mosfet. of course, efficiency will be lower. 

    solution 2: set a higher OC value. 

    BRs, 

    Edwin.