UCC21750-Q1: SiC MOSFET DESAT protection

abhishek deshmukh

Part Number: UCC21750-Q1
Other Parts Discussed in Thread: UCC21750

Hello,

As per UCC21750-Q1 datasheet, the DESAT detection threshold is typically at 9.15V.

I am using SiC MOSFET with 20mΩ RDS ON resistance. Considering peak current of 57A, series diode drop of 0.7V & series resistor drop of say 2V, the total voltage comes to be 3.84V (57*0.02+0.7+2).

This is far less than the threshold of 9.15V.

How this DESAT protection will help to prevent short circuit / overcurrent condition in this case?

As there is no pull-up value mentioned, can you please suggest how to calculate blanking capacitor & series resistor value?

Regards,

Abhishek Deshmukh

over 1 year ago

+1 Andy Robles over 1 year ago

TI__Genius 13470 points

Hi Abhishek,

Thank you for posting to E2E!

Refer to the FAQ in this link about DESAT protection: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1011100/faq-ucc21750-how-can-we-adjust-the-desat-detection-threshold-in-ucc217xx-iso5x5x

Additionally you can also find a calculator under the UCC21750 product page on TI.com. The "DESAT Calculator" tab in this excel sheet tool will enable you to do quick calculation for DESAT protection.