Thermal properties for EAB450M12XM3

John_Johnsson

Hello,

I am writing to you since I have inquiries about some of your SiC MOSFET models. I am writing a thesis with a large Automotive OEM, and part of the work that we are looking in to is construction and modeling of semiconductors. Right now we are looking at EAB450M12XM3 and E3M0021120K, and the datasheets is somewhat conservative when it comes to the thermal properties.

In order to compare their thermal performance in the current electrical design, they are modeled using the Coulier method. Many other manufacturers provide the time constant and equivalent resistance for their model, but you don’t in plane text. So, I was wondering if it is possible for you to disclose this type of information? And also if you have information about the case-ambient thermal resistance it would be fantastic.

 

Best regards,

John

TBhatia

Hello, thank you for your message. A member of our technical team is looking into your questions and we will respond shortly. 

BlakeNelson

Hi John,

As part of the module support team, I can help you with your questions related to the EAB450M12XM3.

While the information you requested is not in our datasheet, the Cauer model is in the PLECS model (which can be found in plain text on our website for any module). When we fit the Cauer network, we first create a foster network. The values for the EAB450M12XM3 are:

As far as case to ambient thermal resistance, I have used 0.08 K/W for case to fluid in the past. This estimate represents standard thermal grease and a commodity coldplate (e.g. copper tubes in Al, rather than an advanced pin-fin solution). It is my expectation you can outperform this number (i.e. achieve a lower Rth,ext) with even modest investment in your thermal management system, but I prefer using a conservative estimate when making recommendations to customers. I also do not have data to make recommendations for air cooling or more expensive liquid cooling solutions.

I hope that information is helpful. Thanks,

Blake

John_Johnsson

Hey Blake,

thanks for the quick response!

Yeh, I came across the PLECS models .xml file as well, was just curios if there was any further data on it. But then I know and will move on with that information, thanks!

Was also figuring I would use some sort of liquid cooling plate for the actual simulation of the system, looking at < 0.05 R_th. But to have a solid baseline and to compare the components purely objective surrounding the module itself, could it be assumed/compared to less then a TO-247 package? meaning R_th,j-a < 30-40?

BR,

John

BlakeNelson

Hey John,

If I understand your question, you are asking if the module thermal performance (i.e. Rja) would be better than the equivalent die in TO-247 packages?

Yes, it would be. The power module has a ceramic for isolation to the baseplate which offers a much better ratio of electrical isolation to thermal conductivity than any isolation solution available for TO-247 MOSFETs. Additionally, the baseplate of the module allows for integration to a large high performance coldplate which should have better Rcf (case - fluid) than a discrete solution. Finally, the module has multiple layers where thermal spreading can occur that would also reduce Rcf. So in general, our power modules should have better thermal performance than the TO-247 parts.

Let me know if I did not understand your question correctly.

Blake

John_Johnsson

Hi,

yes you did, thank you very much for the information!

As a last question, do you have any preliminary LTspice models for the EAB405M12XM3? I saw in some other threads that you guys sometimes could provide models even if they are not 100% complete yet.

BR,

John

Bdeboi

All SPICE models can now be found on our website at https://www.wolfspeed.com/tools-and-support/power/ltspice-and-plecs-models/

Hi John,

Here is a preliminary CAB450M12XM3 model. Its electrical and thermal characteristics are identical to the EAB450. Please let me know if you have any questions on how to use the model.

Thanks,

Brian

TBhatia

Hi, I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.