LM25017: 48V Input and 300W Output Flyback Requirement

Francis Jiang

Intellectual 2080 points

Part Number: LM25017
Other Parts Discussed in Thread: LM5158

Tool/software:

Hi Team,

Customer need a 48V input and 300W output Flyback, and I promote TI Fly-buck to him. But I am concerned the max power of LM25017, customer has 2 output: 12V & 5V, total 300W, could you please help provide your professional advice here? Thanks.

BRs,

Francis

1 month ago

0 Youhao Xi 1 month ago

TI__Guru* 76035 points

Hi Francis,

Thank you for reaching out but the LM25017 is a converter able to support buck or fly-buck toplogies but not flyback topology. And it's peak currentlimit limited having a peak current limit of ~1.2A, so it is far less powerful than the 300W need.

And, flyback is usually a good choice for <75W, although you can stretch a design to deliver 300W. Let me forward this to HVC group and they have flyback controllers which may do the job.

Regards,

Youhao

0 Francis Jiang 1 month ago in reply to Youhao Xi

TI__Intellectual 2080 points

Hi Youhao,

Sorry for confused, the output power is 30W.

For the Flyback, I think our Fly-buck can also achieve isolation, right? And customer input is just 48V, so that's why I promote Fly-buck but not Flyback.

BRs,

Francis

+1 Youhao Xi 1 month ago in reply to Francis Jiang

TI__Guru* 76035 points

HI Francis,

No, you cannot to use it to support 30W. The output current is limited to about 0.65A. For 30W, you will need 2.5A for 12Vout assuming 5V rail is no load.

Please choose a flyback, and 30W is at the sweet spot for it.

Thanks,

Youhao

0 Francis Jiang 1 month ago in reply to Youhao Xi

TI__Intellectual 2080 points

Hi Youhao,

Thanks for your check up, I understood.

How about LM5158?

BRs,

Francis

0 EricLee 1 month ago in reply to Francis Jiang

TI__Guru 51891 points

Hello Francis

Please create a new post if you have a question about LM5158.

-EL

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LM25017: 48V Input and 300W Output Flyback Requirement