Automotive Semiconductors and Functional Safety
Which best describes how IGBTs, SiC MOSFETs and GaN HEMTs are chosen for power conversion in electrified vehicles?
- AGaN HEMTs are superior at every voltage, so it is common to replace everything with GaN, including 1200 V class traction inverters
- BIGBTs switch the fastest, so they are best suited to small DC-DC converters operating at high frequencies in the MHz range
- CSi IGBTs and SiC MOSFETs are used for high-voltage, high-current traction inverters, while GaN is increasingly adopted in on-board chargers and DC-DC converters that are made smaller by using high frequencies
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Answer: C. Si IGBTs and SiC MOSFETs are used for high-voltage, high-current traction inverters, while GaN is increasingly adopted in on-board chargers and DC-DC converters that are made smaller by using high frequencies
IGBTs handle high voltage and high current at low cost, but tail current at turn-off makes them unsuitable for high frequencies. SiC MOSFETs have low losses even in the 1200 V class and are increasingly adopted in applications such as 800 V traction inverters. GaN HEMTs excel at particularly fast switching at the 650 V class and below, and are beginning to be used in on-board chargers and DC-DC converters where higher frequencies are wanted to shrink components. It is important to choose for each application by comparing material properties and cost.
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