Selecting A Freewheeling Diode Solution For Lowest Losses With SiC MOSFETs

Focus:

This article discusses a few of the potential configurations available to implement the freewheeling device in a SiC-based system. These include use of a discrete SiC Schottky barrier diode (SBD), a SiC MOSFET’s body diode, and a SiC MOSFET in combination with an additional discrete anti-parallel SiC SBD. The main objective here is to assess the impact of adding anti- parallel SiC SBDs to SiC MOSFETs on converter losses. To that end, the authors have conducted a series of experiments to determine the switching losses produced by the three freewheeling device options. These experiments are described along with an analysis of the results and discussion of the tradeoffs of each freewheeling device option. Then, some guidelines are presented to help designers select the freewheeling diode solution that will minimize losses in their applications. This discussion includes recommendations on how to size the anti-parallel SBDs, when their use is appropriate.

What you’ll learn:

• How to optimize freewheeling device selection when designing with SiC MOSFETs
• How to size an anti-parallel SiC Schottky diode for use with SiC MOSFETs
• How to measure switching losses and charge characteristics of freewheeling devices in a half bridge circuit

View the Source

Author & Publication:

Xuning Zhang, Monolith Semiconductor, Round Rock, Texas and Levi Gant, Littelfuse, Chicago, Ill., How2Power Today, Jun 15 2018

This article summary appears
in the HOW2POWER Design Guide.

The Design Guide offers
organized access to
hundreds of articles
on dozens of power conversion
and power management topics.

The Design Guide search results
include exclusive summaries
and accurate "how to" analysis
to help you make faster,
more informed decisions.

Search
for more articles