LM51772: How Can I design a power Board with LM51772 multiphase work in parallel

feng

Part Number: LM51772
Other Parts Discussed in Thread: LM51770, PMP23377

Tool/software:

Hi, TI's experts

I have a design task that input range is : 9 - 40V voltage input, 1kW power output with 12V voltage, which means a more than 80A output current.

So I have to find a chip can output 20A current and can be config work in multiphase parallel. then I find LM51772, whcih is a buck-boost controller with extenal MOS and can work in parallel.

But, I can only find the LM51772 work in 2 parallel chip, in that case, the board can not deliver a 1kW output power. It need 4 chip work in parallel can deliver a 1kW power with good thermal condition. in my opinon

So, my question is, can LM51772 work in 4-chip parallel to deliver a 1kW power. If can't, what else choice can I have

1 day ago

0 Brigitte 21 hours ago

TI__Guru 65470 points

Hello feng,

Please have a look at this reference design: PMP23377 reference design | TI.com

It uses LM51770 and I think that this might be the right device for your solution.

The input and output voltage ratings are different, but you can see the paralleling there. In addition, you find on how to parallel the devices in the datasheet application section.

Best regards,
Brigitte

0 feng 3 hours ago in reply to Brigitte

Prodigy 180 points

Hi, Brigitte

Thanks for your reply.

But as the PMP23377 test report said, the 1.2kW output power is made by output voltage of 53V and deliver a 23A current. Which means, the board also have a 20+A output current, in that case, if turn the output voltage to 12V, then the output power would be like 250W.

In the datasheet of LM51770, I can only find two chip work in parallel in multiphase application shown as below, and that means it has the same output capability to LM51772, can not reach the rated 1kW output power design target

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LM51772: How Can I design a power Board with LM51772 multiphase work in parallel