LM5122: LM5122 no output

user5324736

Prodigy 40 points

Part Number: LM5122

I used LM5122 to design a product, as shown in the schematic diagram.I'm debugging now, but I find LM5122 no output.
And VCC is 7.5V, BST is 23.4V. And Input voltage is 13V. It seems normal.
- Is there any problem with my schematic?
- Thanks!

over 6 years ago

0 Garrett Roecker over 6 years ago

TI__Mastermind 21720 points

Hi Jianli,

Thanks for reaching out with you question.
Please reduce the value of R4 to 2Ohm. 100Ohm is too large of a value.

Thanks,

Garrett

0 user5324736 over 6 years ago in reply to Garrett Roecker

Prodigy 40 points

Hi Garrett Roecker ! Thanks!
I reduce the value of R4 to 2Ohm and LM5122 no output yet.
Could you have any better advice?
Thanks!

0 Garrett Roecker over 6 years ago in reply to user5324736

TI__Mastermind 21720 points

Hi Jianli,

Here are a few more suggestions

1. Change D1 to a Schottky diode. This is recommended for the for the boot-strap diode. I signal diode is typically too slow.
2. What is the voltage on the UVLO pin?
3. What is the voltage on the SS pin?
4. What is the voltage on the COMP pin?

Thanks,

Garrett

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LM5122: LM5122 no output