LM51551-Q1: Filter on SEPIC architecture output for making +/- 60 V form 11 V input

Behnam Madadnia

Intellectual 360 points

Part Number: LM51551-Q1

Tool/software:

Dear Engineers,

In the following reference design form TI, would you please let me know what is the role of R4 and R10?

Should I consider them as load?

The Previous stage is an PI filter, for filtering the high frequency elements ?

Regards,

1 month ago

+1 Moritz 1 month ago

TI__Expert 6795 points

Hi Behnam,

Thanks for reaching out.

R4 and R10 are dummy loads.

You are right, these are lowpass pi-filters.

Best regards

Moritz

0 Behnam Madadnia 1 month ago in reply to Moritz

Intellectual 360 points

Hi Moritz,

Would you please let me know if I need to put these resistors in my circuit? sometimes my circuit can be without any load and sometimes there will be load, so what is the best strategy? can these resistors effect my load? the maximum power that the circuit can deliver to my load?

Regards

+1 Moritz 1 month ago in reply to Behnam Madadnia

TI__Expert 6795 points

Hi Behnam,

These resistors are used to always have a minimum load to gat better cross regulation regulation.

If you leave them away, it is possible that the negative rail will run away under no load condition.

Best regards

Moritz

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LM51551-Q1: Filter on SEPIC architecture output for making +/- 60 V form 11 V input