LM5141-Q1: thermal analysis

Sathish Raja

Part Number: LM5141-Q1
Other Parts Discussed in Thread: CSD18503Q5A

Hi,

We are using the LM5141-Q1 regulator for 24V input and 5V output with the output current rating of 20A .The suggested Mosfet (SQJ850EP) in the datasheet fails in thermal analysis .

Could you please guide us through the thermal characteristics of that Regulator and mosfet and could you suggest any other Mosfet with the higher rating..

over 4 years ago

0 Andy Chen over 4 years ago

TI__Mastermind 27045 points

Hi Sathish,

Pls provide more detail information:

1. Vin 24V variation range

2. Switching freq, suggest below 500KHz

3. maximum continuous load current

4. Max ambient temp?

0 Sathish Raja over 4 years ago in reply to Andy Chen

Prodigy 210 points

Hi,

1.Vin - 16-24V with 5% tolerance

2.We have planned to 1Mhz

3.Max-cont load current-20A

4.50C

0 Andy Chen over 4 years ago in reply to Sathish Raja

TI__Mastermind 27045 points

Hi Raja,

Pls try below MOSFET in your design:

CSD18503Q5A 40V, N ch NexFET MOSFET™, single SON5x6, 4.3mOhm

You may start with Fsw=400KHz, then gradually increase freq till the controller Tj and FET temp reach max limitation.

B R

Andy

Power management

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LM5141-Q1: thermal analysis