Thermal model

raghava235

Hai,

Greetings.

We are developing a dc circuit breaker design for which we require high efficiency. We are planning to use cpm3-1200-13A devices. However, the datasheet has not provided the die sizes. Also, we require the dynamic thermal performance of the die at high currents for a short time. To say specifically, When a fault occurs, the current ramps in the die and then we will sense the current and turn it off. So how much of a ramp current can the die bear, and what is the temperature rise in the die? If you have any reference data on the temperature rise based on any layouting. I request you to please provide. Thank you. The dies are really making our design compact. So we are looking forward to using them. Please provide the required details. If any cauer model is developed from experiment results please share. Here I am attaching few images of the desired thermal model we are expecting. THank you

TBhatia

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

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 Raghava,

Beyond extremely short time scales, the current limit and temperature rise of the die in your application will ultimately be determined by your thermal interface since you are using bare die. In addition, we can't guarantee any reliability above the pulsed 300A limit specified in the CPM3-1200-0013A datasheet. However, while I can't provide any information specific to your implementation, I can provide you an example device that uses a similar thermal stackup/ceramic and the CPM3-1200-0013A die. I've attached an LTspice model of the WAB400M12BM3 power module that includes a Cauer network for each switch position. You can view this Cauer network within the "WAB400M12BM3.asc" file. This module has four 13 mΩ die in parallel at each switch position, so you will need to account for that when performing your analysis. In addition, the Cauer network is not fit below pulse widths of 1 us, so any temperature rise in time scales smaller than this may be unreliable. If you have any questions about how to operate the model, please feel free to reach out. I should note that this model is preliminary, and may contain some error in predicting the device behavior during switching.

For specifications on the die dimensions, please contact the sales team at the link found on this page: https://www.wolfspeed.com/products/power/sic-bare-die-mosfets/

raghava235

Thank you for the reply.

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.