-48Vinput to 12Volt 4Amp output looking for a part

Timothy Darling40

Prodigy 40 points

Other Parts Discussed in Thread: LM5021, LM5122, PMP20371

Hello

I am doing a design where the backplane voltage is -48V, output is 12v at about 4Amps. Does TI have a part for that?

Also why use -48V? Does it have to do with relability of the connections?

Thanks

Timothy Darling

Designer

over 8 years ago

0 Peter Meaney over 8 years ago

TI__Mastermind 31580 points

Hi Timothy,

I have asked on our engineers to respond to your post. You should see a response soon.

Regards

Peter

0 Yunsheng Qu over 8 years ago

TI__Genius 9790 points

Hi, Timothy

Is the input voltage -48 constant, and do you need isolation for this power you are going to design?

If isolate is needed, LM5021 is my recommendation.

If isolate is not needed, you should post your question on below forum.

https://e2e.ti.com/support/power_management/non-isolated_dcdc/

-48 connection, means positive port connect to ground. This connection is going to protect power supply from damage.

Regards,

Yunsheng

0 Colin Gillmor over 8 years ago in reply to Yunsheng Qu

TI__Mastermind 25570 points

Hi Timothy

-48V reduces corrosion versus +48V. Particularly in telecoms systems. Search for 'cathodic protection' for more information - I'm not an expert on corrosion.

Regards
Colin

0 LeonardEllis over 8 years ago

TI__Guru 71526 points

Hi Timothy,

I encourage you to use the TI Reference Designs page: http://www.ti.com/general/docs/refdesignsearchresults.tsp

I used -48V Min Input, 12V Min Output, no value in Output current, and a close design is the 125W Inverting Buck-Boost using the LM5122:

125W Inverting Buck Boost for Telecom Power Amplifier Reference Design . This PMP20371 would be a good starting place for your design, you can modify it for your requirements.

~Leonard

Power management

Power management forum

-48Vinput to 12Volt 4Amp output looking for a part