Design of Short-Circuit and Overload Protection Chips for SiC MOSFETs

This paper proposes a fast short-circuit (SC) and overload (OL) protection integrated circuit (IC) for silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). The method achieves short-circuit protection (SCP) by detecting the voltage drop across the inductance between the Kelvin source and power source of the SiC MOSFET, which is generated by the di/dt. OL protection is achieved by detecting the current and voltage of the SiC MOSFET, thereby accumulating energy for protection. The proposed protection IC is implemented using a 0.5 µm Bipolar-Cmos-DMOS (BCD) process, with a chip area of approximately 2 mm². The effectiveness of SC and OL protection is validated on a 1200V/80mΩ SiC MOSFET test platform. Experimental results show that when a SC fault occurs in the SiC MOSFET, the chip can detect the fault and safely turn off the device in approximately 150 ns. Similarly, when an OL fault occurs, the chip can quickly detect the fault and shut down the device.