LM5140-Q1: Regulator Design: LM5140-Q1

Reshma V

Part Number: LM5140-Q1

Hi Team,

I'm using LM5140 DUAL Buck controller in my design.

The current requirement are: 25A@3.3V, 8A@5V.

The calculator tool shows the efficiency of the regulator drops above 20A current for 3.3V output.

Attached the values considered in the calculator tool.

What is the maximum output currents supported by each outputs?

0 Andy Chen over 2 years ago

Hi Reshma,

25A for one channel is challenge design for 6V--28V input range. do you have air flow for cooling?

low side RDS(on) should below 3mohm if no air flow. you may use one 6mohm FET for high side and parallel 2pcs 6mohm FET for low side.

B R

Andy

0 Reshma V over 2 years ago in reply to Andy Chen

Hi Andy,

Can you suggest high side and low side mosfets for the same.

And is the compensation network values considered optimum?

0 Andy Chen over 2 years ago in reply to Reshma V

Hi Reshma,

You may select the FET by key spec:

VDS 35V--50V

RDS(on) about 6mohm at Vgs=5V

Ciss the lower the better

Do you have prefer supplier for the FET?

Compensation design depends on the target loop cross over freq, Actual Cout and ESR. you can design it with the calculation tools.

B R

Andy

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