transient Drain-to-Source Voltage

raghava235

Hai,

Our application is DC circuit breaker design using SiC devices. We plan to use cpm3-1200-0013a bare dies or modules with the same dies (CAB760M12HM3). In our application, we have inductors in series with devices. When we turn off the switch, there will be a voltage spike across devices. We can use TVS diodes or MOV to suppress the voltage for that. However, there is a short voltage spike (Vds) of a few microseconds (image attached). So I request you to let me know the transient voltage withstand capability of the above die and modules along with the pulse time. 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. 

AustinC

Hello raghava235,

To be pedantic, the CAB760M12HM3 utilizes the 16 mΩ CPM3-1200-0016A die, but the answer is the same for the 13 mΩ die: the image you included is of no concern for a 1200 V rated SiC MOSFET. The peak voltage you measured was < 1200 V, which is well within the intended operation of this device.

Expanding further, the breakdown voltage of either of these devices is typically around 1400 V - 1500 V, and breakdown is not an instantaneous failure mechanism in the SiC MOSFET like it is in other semiconductor devices. The body diode of the MOSFET will avalanche for some time before the device fails. I can't provide an avalanche rating for the 13 mΩ die, but as a reference, another of our SiC MOSFETs has an avalanche capability of ~2.5 J and an avalanche withstand time of approximately 25 µs when tested according to AEC-Q101.

One thing to keep in mind is that paralleled devices (such as in the CAB760M12HM3 power module) each have a slightly different breakdown voltage due to part-to-part variability and do not equally share energy during an avalanche condition. One device will avalanche first and be subjected to all of the avalanche energy; therefore, the avalanche rating is set by the device and not affected by the number of devices in parallel.

Best Regards,

Austin

raghava235

Thank you.