Page 12 - PEN Ebook March 2021

Cover Story - Design SEMICONDUCTORS

How to kill a SiC MOSFET

– Errors in Gate Circuit

Figure 5: Infineon/Spark Connected reference design roadmap for wireless charging.
Design and their impact

ure 5). The solution portfolio ranges from a 2 W 100 W inductive solution for robots and industrial
inductive solution for low-power IoT devices (The applications (The Ogre). It also features resonant
Pegasus) over a 10 W inductive solution for sub- solutions for more positioning flexibility. on robustness
surface smartphone charging (The Kraken) to a

By Mehrdad Baghaie Yazdi, Martin Warnke, ON Semiconductor
For More Information

The emergence of SiC MOSFETs in various topol- dampening oscillations on the gate, in order to
ogies has resulted in great performance and improve switching transients actually results in
▶ Additionally, Spark Connected recently achieved a technological breakthrough efficiency improvements. However, if not used heavy stress on the gate. This stress is not easily
of scaling the power level up to 300 W charging. It made it possible to bring even correctly, engineers can quickly find themselves visible through measurements, as they occur on
frustrated with device failures. These failures the internal gate node and not on the external
higher-power wireless charging to the market.
are often, quite in contrast to the perception of measurable one which, thanks to the C , seems
GS
the customers, not intrinsic weaknesses of the nicely dampened. Furthermore, we discuss the
▶ To discover Infineon's highly reliable and broad-scale wireless charging solutions
SiC MOSFET technology but in the design choic- attention that has to be given to the SiC MOS-
that meet all essential design requirements, please visit our dedicated Infineon es around the gate loop. Particularly the lack of FET body diode. There are many misconceptions

website. attention to the turn-on interactions between the around the body diode of SiC MOSFETs, to the
high side and low side device can result in cata- point that even veteran technologists sometimes
▶ To learn more about how Spark Connected is transforming wireless power delivery strophic failures excited by wrong circuit choices. believe that this body diode is reverse recovery
In this paper, we show that classical dampening free. Indeed, we show that the body diode of SiC
with innovative platforms and disruptive technology that benefit a wide variety of
efforts using gate source capacitors in the gate MOSFETs, in particular planar gate devices, can
applications, please visit www.sparkconnected.com.
circuit loop are a great hazard and an often-hid- be a culprit in causing damage to the gate.
den killer of SiC MOSFET gates. This practice of

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