LM5001: negative to negative buck converter (-5V to -2.8V)

Shinichi Inoue

Guru 21566 points

Part Number: LM5001

Tool/software:

Dear Specialists,

My customer is looking for negative to negative buck solution.

At related thread, I understand LM5001 is available.

Could you please answer following questions?

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(1) Could you please let me know what the new product can.

(2) Is it possible to use for -5V to -2.8V?

(3) Could you please provide a document for negative to negative buck design?

I could not obtain pdf file attached in the related thread.

Also, could you please share any other reference documents?

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I appreciate your great help in advance.

Best regards,

Shinichi

4 months ago

0 Mounika Girish 4 months ago

TI__Intellectual 2426 points

Hello Shinichi,

The responsible engineers for this device are out to office. Please expect a response, begining of next week.

Best regrads,

Mounika

+1 Niklas Schwarz 4 months ago in reply to Mounika Girish

TI__Mastermind 29710 points

Hi Shinichi,

Sorry for the long delay and thanks for already looking at other e2e threads to find an answer.

1. LM5001 is an asynchronous boost converter. It should work for this application, but there are also newer converters with similar specs, which are overall more modern. The newest part in this field would be LM5158.

2. Yes, you should be able to use this device for your given parameters.
I have little experience with building such designs myself, but I can refer to several documents, which should provide enough information on how to implement the circuit.

3. The document you might have found in another e2e thread should be this one:
The Parallel Universe of Negative Input Voltages (1).pdf

Another helpful document can be found here:
https://www.ti.com/lit/an/slvaf68/slvaf68.pdf

Please let me know if you have additional questions on this design.

Best regards,
Niklas

0 Shinichi Inoue 4 months ago in reply to Niklas Schwarz

Guru 21566 points

Hi Niklas,

Thank you for your reply.

In the case of negative to negative, the feedback circuit needs to be level shifted.

This seems to be a bottleneck.

I will ask the customer to consider an inverting type as well.

I appreciate your great help and cooperation.

Best regards,

Shinichi

+1 Niklas Schwarz 4 months ago in reply to Shinichi Inoue

TI__Mastermind 29710 points

Hi Shinichi,

Yes, you are correct about the level shifter.
Feel free to come back to me if any more customer questions come up.

Best regards,
Niklas

0 Shinichi Inoue 4 months ago in reply to Niklas Schwarz

Guru 21566 points

Hi Niklas,

Thank you for your reply.

When the customer has an additional question, I consult with you.

I appreciate your great help and cooperation.

Best regards,

Shinichi

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LM5001: negative to negative buck converter (-5V to -2.8V)