LM5116 +48V input with +12V output @8A and EVM

Grant Downie2

Intellectual 390 points

Other Parts Discussed in Thread: LM5116, LM5116-12EVAL

Dear Sir/Madam,

I am planning to use the LM5116 in an application that has the following parameters.

Input : +48V

Output : +12V@8A.

I don't have any experience with this part so some advice would be much appreciated.

The schematic based on the web bench design is shown:

3681.48vdc.pdf

Q1. Are there any issues with using this controller to produce +12V @ 8A from a +48V input?

Q2. I plan to test using the +12V EVM part number LM5116-12EVAL/NOPB to test. With some minor component

changes is it possible to get 8A from the EVM?

Regards Grant

over 10 years ago

0 EricLee over 10 years ago

TI__Mastermind 46141 points

A1. It is okay. No issue.

A2. It is possible with some minot component change.

Here are some more comments;

- A RC snubber from SW to PGND is recommended.

- Reserve a zero ohm jumper from 'POWER +12 VOUT' to VCCX pin.

Regards,

0 Grant Downie2 over 10 years ago in reply to EricLee

Intellectual 390 points

Hi Eric,

Thank you.

I will make changes as per EVM for snubber C23 and R14. Also +12V to VCCX R13.

There are several cases of LM5116 being damaged if you search through E2E which is a concern.

Are there any additional comments to make LM5116 robust?

Regard Grant

0 EricLee over 10 years ago in reply to Grant Downie2

TI__Mastermind 46141 points

We haven't noticed any issue on LM5116's absolute maximum rating.

When you first turn it on, please starts from low Vin, low Iout and measure critical point (SW node ringing) and critical component temperature (MOSFETs, IC) frist.

Regards,

Power management

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LM5116 +48V input with +12V output @8A and EVM