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PCIM - DESIGN PCIM - Design

SIC DESIGN

“Getting the most out of silicon carbide requires you to minimizing losses and reducing cost,” said
Peter Losee, director of device technology at UnitedSiC. “We design a cascode FET with a very low

on-resistance trench vertical JFET, built in silicon carbide in cascode with a low-voltage silicon
MOSFET that’s engineered for cascode use. This allows us to avoid the major problem of channel
resistance that’s placed on SiC MOSFETs.”

SiC will further strengthen the power grid and reduce losses. Tobias Keller, vice president of
product marketing at Hitachi ABB Power Grids, highlighted his experience in the SiC field: “Silicon
carbide already started on the immobility side on voltage levels of 750 V and 1.2 kV. Depending on
conduction and switching losses, SiC will find its way to traction in the industry on voltage levels
of 1.7 and 3.3 kV.”

Guy Moxey, senior director of marketing power products at Wolfspeed, said, “SiC technology can
bring lower conduction loss and lower switching loss, leading to system efficiency improvements and
power density improvements over silicon. Wolfspeed offers a large portfolio for both low-power and
high-power spaces, which is essential to enable more applications to benefit from SiC.”

Mitsubishi Electric just finished launching its second generation of SiC power modules. “These

power modules will be used in a wide range of applications like aircon, medical, electric vehicles,
and hybrid trains,” said Eugen Stumpf, application engineering manager at Mitsubishi.

“Both generations use planar structure; in the second generation, R and gate drain capacitance
DS(on)
are reduced,” he added. “These improvements are done by several features, in particular with the
The Next Wave of SiC introduction of JFET doping technology.”

Peter Friedrichs, vice president of SiC at Infineon Technologies, highlighted three different device

By Maurizio Di Paolo Emilio, editor-in-chief of Power Electronics technologies: CoolSiC, CoolGaN, and CoolMOS. “The key performance indicators are usually
News and European correspondent for EE Times efficiency, size, and reliability,” he said. “To select the right technology depending on the topology
and on the boundary conditions of the application, we define figures of merit. Other important
Power semiconductors are the key to an energy-efficient world. New technologies, such as silicon parameters are reverse-recovery charge, energy stored in the output capacitance, gauge charge,
carbide and gallium nitride, enable higher power efficiency, smaller form factors, and lower weight. and output capacitance. For all of them, we can calculate the figure of merit.”
SiC, in particular, is a wide-bandgap material which is able to overcome the limits offered by
conventional silicon-based power devices. Marc Rommerswinkel, principal client engagement manager at Microchip, has no doubt about the
advantages of SiC compared with silicon-based solutions, such as higher efficiency due to lower

While three-level and other silicon circuit topologies are emerging to improve efficiency, new switching losses, as well as reducing system size, cost, and weight because of higher switching
SiC designs are emerging to meet growing high-power requirements for electric vehicles. During frequency and smaller cooling systems.
PCIM, several speakers discussed topics and challenges related to SiC. For example, SiC remains
considerably more expensive than silicon. Hence, it’s important to identify applications in which “Silicon carbide can be switched very fast, and any parasitic inductance can cause problems
economics keeps pace with energy savings or some other technical advantage to justify the expense. because of ringing and, with that, overshoots and undershoots, which cause EMC issues but also

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