LM5143: 4phase with 90A load(rms/continuous)

Roy Chou1

Genius 16210 points

Part Number: LM5143
Other Parts Discussed in Thread: LM25143

Tool/software:

Hi Team,

As title, does LM5143 recommended to use the condition?(4phase)

To minimized the MOSFET thermal issue, can we use 2MOSFETs in parallel?

If you have any recommendation, feel free to let me know.

Vin : 18-24V

Vout : 12V

Iout : 90A

tr < 40C

We can't sue heatsink in our application.

Regards,

Roy

over 1 year ago

0 Timothy Hegarty over 1 year ago

TI__Guru 74462 points

Hi Roy,

It is possible to run at 22.5A/phase at that input voltage, and you can use the LM25143 42V input version of that controller family.

Please complete the quickstart calculator and send for review.

Regards,

Tim

0 Roy Chou1 over 1 year ago in reply to Timothy Hegarty

TI__Genius 16210 points

Hi Tim,

To minimized the MOSFET thermal issue, can we use 2MOSFETs in parallel?

Regards,

Roy

0 Timothy Hegarty over 1 year ago in reply to Roy Chou1

TI__Guru 74462 points

Sure, if you want to. My understanding is that it's better to use one good FET as opposed to two mediocre FETs in parallel. This gives a better PCB layout with a tigher switching power loop (lower parasitic inductance). Also, paralleling two FET gives half the Rdson but double the capacitance, so it's really only suitable for 400kHz and below.

Regards,

Tim

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LM5143: 4phase with 90A load(rms/continuous)