LM25143-Q1: LM5143DESIGN-CALC question

CHO SR

Genius 3415 points

Part Number: LM25143-Q1

Hi,

The customer wants to use LM25143-Q1.

Spec 1 : Dual Output

Input Voltage : 21~27V

1Ch Output Voltage : 12.5V

1Ch Output Current : Max 30A ( Typ 25~27A )

2Ch Output Voltage : 12.5V

2Ch Output Current : Max 30A ( Typ 25~27A )

Spec 2 : Single Output

1Ch Output Voltage : 12.5V

1Ch Output Current : Max 30A ( Typ 25~27A )

Q1. Can use it with 2 specifications?

Q2. Or, please recommend a product that meets the single output specification.

+1 Timothy Hegarty over 2 years ago

Hello,

Yes, the LM25143-Q1 works here. Please use the quickstart calculator to optimize your design.

Regards,

Tim

0 CHO SR over 2 years ago in reply to Timothy Hegarty

Genius 3415 points

Hi Tim,

Thank you for your support.

Customer has created a single output-2 phases calculator.

Please review it and give me advice on improvements.

And please explain the interpretation on the Bode Plot.

+1 Timothy Hegarty over 2 years ago in reply to CHO SR

Hi Cho,

Thanks for sending the quickstart file. Here are some notes:

4mΩ gives 33.8A, which is a bit tight for current limit. 3mΩ gives 46A or ~50% margin.
The inductor can be 3.3uH. 5.6uH gives low ripple current of 18% (30-40% is the norm).
Check Cout is the effective value (e.g. derate for voltage with a ceramic).
The loop parameters look fine. Crossover target is 10-15% of Fsw and phase margin is > 45 degrees.
40V FETs should be fine for this application.

Regards,

Tim

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