April 2015

DocID027654 Rev 1

1/17

www.st.com

AN4671

Application note

How to fine tune your SiC MOSFET gate driver

to minimize losses

L. Abbatelli, C. Brusca, G. Catalisano

Introduction

Power electronics today is about the constant pursuit of efficiency improvements as well as cost and

size reduction.

In this challenging power conversion scenario, silicon carbide (SiC) power switches are gaining

prominence: for 1200 V power switches, silicon carbide MOSFETs are becoming an increasingly viable

alternative to conventional silicon technologies. The advanced and innovative properties of wide band-

gap materials help ensure that ST’s SiC MOSFETs exhibit low on-state resistance*area in comparison

with silicon MOSFETs, even at high temperatures, and excellent switching performance versus the best-

in-class 1200 V IGBTs in all temperature ranges, thus simplifying the thermal design of power electronic

systems.

With far lower switching losses than for comparable Si-based switches, SiC devices can operate at

switching frequencies two to five times greater than present devices and overall system designs can

also benefit from smaller and lighter passive components. The very low leakage currents boost system

reliability and consistency even when subject to elevated reverse voltages or temperature increases.

This all means that the efficiency delivered by a SiC MOSFET in any application is significantly higher

than silicon-based solutions, especially at high frequencies.

It is therefore crucial to drive SiC MOSFETs in such a way as to facilitate lowest possible conduction

and switching losses, which is why this document explains the main principles for obtaining the best

performance from ST’s 1200 V SiC MOSFET in your application.

The first ST SiC MOSFET given is the 80

mΩ version (SCT30N120), the device is packaged in the

proprietary HiP247™ package and features the industry’s highest junction temperature rating of 200 °C.

All the data reported in the present work refers to the SCT30N120.