SiC Power Schottky Diodes in Power Factor Correction Circuits

Focus:

This article discusses the characteristics of SiC Schottky diodes and their impact on the operation of continuous-conduction mode (CCM) power factor correction (PFC) boost converters. In PFC boost converters, the replacement of silicon PiN diodes with SiC Schottky diodes enables higher efficiency and lower MOSFET case temperatures at a given switching frequency, or an increase in switching frequency (for smaller size) while maintaining the same efficiency. The SiC Schottkys also reduce parts count by eliminating the need for snubber components. Another benefit is the possible reduction in MOSFET gate resistance, which lowers MOSFET switching losses. The advantages of the SiC Schottkys are illustrated by evaluating the performance of a 390-W power supply with its original silicon PFC diode and then with a SiC Schottky PFC diode. In the first case, measurements are taken with the originally silicon PFC diode, silicon snubber diode, and passive snubber components installed. Then, the PFC diode was replaced with a SiC Schottky, snubber components were removed, and the measurements were repeated. Since the power supply originally employed two paralleled MOSFETs in the boost converter, the use of the SiC PFC diode also made it possible to remove one MOSFET and repeat measurements of switching waveforms, efficiency, and case temperatures. These measurements illustrate how the SiC Schottky reduces MOSFET requirements for the boost converter.

What you’ll learn:

• How to understand the efficiency, size, and component count benefits of using a SiC Schottky diode as the boost diode in CCM PFC boost converters

Notes:

The publication date on this article is not clearly specified in the document. However, according to author Ranbir Singh, this article was published in late 2002, possibly October or November 2002.--David Morrison, Editor, How2Power.com

View the Source

Author & Publication:

Ranbir Singh and James Richmond, Cree, Vendor website, Nov 01 2002

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