Doubt in the Xml file CAB6R0A23GM4T

Jyoti

Hi,

I am using CAB6R023GM4T xml file provided by Wolfspeed in one of my converters for the loss-thermal analysis. I am using PLECS as the simulation platform. I am having few doubts the xml file.

1. Why thermal chain is provided in the xml file of both the SiC MOSFET and and its body diode although they are a single device. Will it not result in the different junction temperatures of MOSFET and its body diode? Different conduction and switching losses may result in their different junction temperature. Since, they are on the same chip both the MOSFET and its body diode should have the same temperature.
2. Why the turn-off losses of the body diode is kept as zero in the xml file, although the reverse recovery energy vs junction temperature shown in the datasheet of CAB6R023GM4T (Fig. 14 ) does not appear low enough to be ignored?
3. The reverse recovery shown in the datasheet is for current of 200 A. Does it vary linearly with current? How is the reverse recovery energy variation with temperature?

Please help me with these queries asap.

Thank you,

Jyoti

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

BlakeNelson

Hi Jyoti,

The limitations of the PLECS model you have pointed out are known and we are currently working on an update to our model library to address this. Here is an early look at the model we are developing:

Wolfspeed_Integrated_PLECS_lib.zip

This new library uses an integrated model so that the MOSFET junction can include the diode losses (both conduction and Err). It requires some additional setup as it does not use the default PLECS MOSFET model. We are working on some user documentation to help with its implementation, but there is a text file included in the zip file which explains installation. I'm also happy to address any questions you may have.

So far, the models I can provide in this format are somewhat limited (the model file for CAB6R0A23GM4 is included in the zip, but let me know if you have any others you need and I will attempt to provide them); we hope to release a complete library relatively soon. Some of our older datasets are missing Err, so even once the integrated model is released, not all of the models will include Err.

As for your questions related to the CAB6R0A23GM4 specifically, I would point you towards figures 11 through 16 in the datasheet. Based on Fig 11 / 12, Err has a linear relationship with current, but it is relatively small. Figure 14 shows the relationship between Err and temperature is much more dramatic than the current relationship.

Please let me know if you feel any of your questions need additional details or if you have other questions.

Thanks,

Blake