LM25149-Q1: Is this part support for 40A load? My input is 24VDC and Output is 12V/40A is this the right part to use.

Sagar Watane

Part Number: LM25149-Q1
Other Parts Discussed in Thread: LM25149, LM5149-Q1EVM-400, PMP20804

LM25149-Q1 Is this part support for 40A load?

My input is 24VDC and Output is 12V/40A is this the right part to use.

if not suitable then suggest the part which can be best suited for my application.

Requirement is:

Input is 24VDC and Output is 12V/40A

and the part must have ultra-low IQ and integrated active EMI filter.

0 Orlando Murray over 1 year ago

Sagar,

LM25149 is a suitable controller yes.

At load current larger than 10A, the temperatures of MOSFETs and inductor usually get extremely hot, due to I^2 * R losses growing exponentially.

Those temperatures are usually the limiting factor

You can reference the 12V EVM, LM5149-Q1EVM-400, at 8A the inductor and MOSFETs are 80-90C case temperature.

You can try to do a dual-phase example as shown in the datasheet, and split the phase current into 20A/phase.

This will still get hot, and likely require active cooling or dual MOSFETs.

Alternatively you can try 4-phase for 10A /phase which will be more manageable temperature wise.

4-phase requires external clock generation for 90 and 270 degrees phases, as the device only outputs 180 degrees.

Hope this helps,

-Orlando

0 Sagar Watane over 1 year ago in reply to Orlando Murray

Hello Orlando, Right, Agree with you!

Is it any 4-phase for 10A /phase standard design is available with LM25149-Q1 or any EVM to verify? kindly share.

Also suggest any 40A readily available proven design to refer and further evaluation.

0 Orlando Murray over 1 year ago in reply to Sagar Watane

Sagar,

no not yet, a 4-phase design for a similar device is in progress.

You can search our reference designs:

From that list, the 2-phase buck is PMP20804

Hope this helps,

-Orlando

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