Effect of Optocoupler Gate Drivers on SiC MOSFET

SiC MOSFETs have shown improved features like high switching speeds, high voltage and junction temperature withstanding capacity and low conduction loss. Hence, these are used in applications like high power density matrix converter, traction converter, and many other converters. Conventionally, pulse transformer, bootstrap, and optocoupler gate drivers drive power electronic devices reliably and safely. Since SiC MOSFETs are high switching speed devices, therefore, the gate drivers proposed in the literature for SiC MOSFETs are Active, Resonant, Gate-boost, and GaN-digital-isolator. These drivers tackle the side effects of high switching speed but are complex, costly, and space consuming. Therefore, the simpler, cheaper, and smaller sized optocoupler based driver is best suited. However, optocoupler based drivers with safe operating area (SOA) protection features have shown erroneous results. Moreover, simple optocoupler based gate drivers have not been tested with SiC MOSFETs in the literature. This paper compares two types of optocoupler based gate drivers driving SiC MOSFETs. These are simple and SOA featured optocoupler based gate drivers. The SOA featured optocoupler based gate driver has an SOA protection feature to protect the switch from damage. An experimental test circuit is used to observe the performance of both the drivers with SiC MOSFETs.