Need a dual isolated and non-isolated buck-boost supply

Stephen Holland

Intellectual 2795 points

Other Parts Discussed in Thread: LM25118-Q1

I need a dual supply solution with the following specs:

8 - 75V input
2 outputs:
- non-isolated 12V 20mA
- isolated 12V 50mA
Automotive rated
Small as possible
low-cost (of course)

I am thinking of the LM25118-Q1 with a coupled inductor output, but I'm not sure if that's the best answer...

Any help is appreciated.

over 9 years ago

0 Peter Meaney over 9 years ago

TI__Mastermind 31580 points

Hi Stephen,

I think we have a tool that may help select the best approach. I need to contact a colleague to find out the link to it.

Regards

Peter

0 David Baba over 9 years ago in reply to Peter Meaney

TI__Mastermind 40090 points

Hi Peter,

I would recommend that you use a flybuck-boost. The LM5160Q can be configured at a inverting buck boost with -12V on the Primary. Use a 1:1:1 turns ratio for the two positive 12V outputs. I have provided a link below to help you understand the topology I am recommending. Also I have attached a conceptual circuit of what I am describing above.

Flybuck Boost.docx

Hope this helps?

Power management

Power management forum

Need a dual isolated and non-isolated buck-boost supply