Page 109 - NEW Armstrong Book - 2

Illustrating the Advantages
SiC MOSFETs Offer in
Power Electronics
By Fanny Björk, Zhihui Yuan, and David Levett
lectrical power designs are driven by market needs for increased efficiency and
improved productivity while conform- ing to regulatory requirements. The overriding end-user need is almost always for smaller, lighter, and more efficient systems, which are made pos- sible by substantial innovations in the design of power semiconductors. While silicon MOSFETs and IGBTs have long been dominant in power semiconduc- tors, recent advances in wide-bandgap (WBG) technology, especially silicon carbide, are delivering additional ben- efits to designers of power electronics systems, with improved efficiencies and higher-voltage capabilities leading to reduced form factors.
This article briefly reviews the benefits of SiC MOSFETs and discusses the key characteristics of SiC devices in order to
Recent advances in WBG technology are delivering additional benefits to designers of power electronics systems.
E
guide device selection based on applica- tion requirements. Two common power electronics applications are discussed to demonstrate how these devices can deliver value to the designer.
From silicon to SiC
The most common power semiconduc- tors available today are silicon-based MOSFETs, power diodes, thyristors, and IGBTs. Silicon MOSFETs dominate the lower-voltage market (<650 V), and IGBTs dominate the higher-voltage market (>650 V). These devices have an easy-to-drive gate, fast switching speeds, low conduction losses, and
the ability to operate in parallel. This has led to widespread adoption across a wide range of applications, including portable devices, mobile phones, lap- tops, wireless network infrastructure, motor drives, and renewable energy technologies such as solar.
While silicon MOSFETs and IGBTs will remain popular choices for many power applications, continued devel- opments in WBG materials have enabled a new range of power appli- cations. SiC especially has the advan- tages of higher thermal conductivity — 120–270 W/mK — and higher current density, compared with silicon.
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