LM5642: To support 40A

David Park

Part Number: LM5642
Other Parts Discussed in Thread: LM25143, , LM25148

Hi,

Could you provide or recommend proper FET or reference circuit to support 40A?

Customer already have done the evaluation for 30A with CSD18503 but there is FET damage from 35A.

Please guide for 40A.

Thanks.

0 Timothy Hegarty over 1 year ago

Hi David,

We typically recommend the LM25143 or 2 x LM25148 instead of the LM5642. Both alternatives are 42V max Vin.

What is the Vin-max, Vout and Fsw for this application (as this affects FET choice)? I assume 40V FETs are adequate. Take a look at our FET selector tool: https://www.ti.com/tool/SYNC-BUCK-FET-LOSS-CALC and this video training: https://training.ti.com/nexfet-synchronous-buck-converter-fet-selection-tool-training.

You can also refer to the LM25143 quickstart calculator to check MOSFET losses for a given application.

Regards,

Tim

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