LM51770: thermal calculation

Wendler Wu

Part Number: LM51770
Other Parts Discussed in Thread: LMG3100R017

Tool/software:

Hello,

Is there any thermal estimate calculator for the module name PMP41155 Power Module which is LM51770DCPR application circuit?
I need to evaluate the thermal for the product design air flow or heatsink.

3 months ago

0 Wendler Wu 3 months ago

Prodigy 120 points

Any update?

0 Brigitte 3 months ago in reply to Wendler Wu

TI__Guru 65470 points

Hello Wendler,

I do not know of any thermal estimate calculator for this specific reference design. If you have a look to the LM51770 quickstart calculator, you could estimate the power dissipation in the lowest portion named Efficiency / Power Loss Analyzer: LM51770-QUICKSTART-CALC Calculation tool | TI.com

Possibly the designer of PMP41155 could help you with a thermal measurement if you share the worst case conditions in your system with him.

Best regards,
Brigitte

0 Wendler Wu 3 months ago in reply to Brigitte

Prodigy 120 points

Hello,

Do you have any GaN power loss calculation or documents for reference?

0 Brigitte 3 months ago in reply to Wendler Wu

TI__Guru 65470 points

Hello Wendler,

I do not see where the calculation for GaN would be different to the calculations of MOSFETs. Please use the quickstart calculator and just enter the GaN information there.

Best regards,
Brigitte

0 Wendler Wu 3 months ago in reply to Brigitte

Prodigy 120 points

Hello,Brigitte

But there's some information not in GaN specification.According the LMG3100R017 datasheet,I can't find the data in red rectangular area.

So I'm not sure how to enter the information here.
quick calculator

0 Brigitte 3 months ago in reply to Wendler Wu

TI__Guru 65470 points

Hello Wendler,

LMG3100 is not a GaN FET, it is a GaN FET with driver. Please let me forward the power dissipation request on LMG3100 to the right person.

Best regards,
Brigitte

0 Wendler Wu 3 months ago in reply to Brigitte

Prodigy 120 points

Hi,Brigitte

OK,I am looking forward the reply.

0 Pratik Adibatla 3 months ago in reply to Wendler Wu

TI__Expert 7473 points

Hi Wendler,

GaN FETs do not have reverse recovery diode, we do not share internal specs like Vth, gfs, Rg and all. We do have simplis/PLECS models and loss sim data which we can provide if you want.

Best,

Pratik A.

0 Wendler Wu 3 months ago in reply to Pratik Adibatla

Prodigy 120 points

Hi,Pratik

That sounds good.I would like the data to study.
Thanks for your sharing.

0 Pratik Adibatla 3 months ago in reply to Wendler Wu

TI__Expert 7473 points

Hi Wendler,

Please reach out through your FAE/TSR for the account as it can be only shared with customers who have NDA with us.

Best,

Pratik A.

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LM51770: thermal calculation