Wide-bandgap (WBG) materials, particularly silicon carbide (SiC) and gallium nitride (GaN), are no longer considered exotic semiconductors. The automotive industry has chosen them for their ability to switch faster, tolerate higher blocking voltages and temperatures, and dissipate less energy than conventional silicon.
The physical and electrical characteristics of SiC and GaN enable improved efficiency in electric and hybrid drivetrains, higher power density, and better thermal management. This article examines the current state and next steps for both technologies across different key automotive areas, including traction inverters, on-board chargers (OBCs), DC/DC converters, and auxiliary power systems.
Traction inverters: the realm of SiC, but GaN makes headway
The transition from a 400-V to 800-V bus architecture, a common trend in electric-vehicle design, has halved the current required to deliver the same power. This reduction, in turn, enables ultra-fast charging, as EVs can absorb more power without incurring hazardous current levels or excessive heating. Moreover, the 800-V bus power delivery significantly lowers internal heat loss and allows for lighter and thinner vehicle wiring.
This architecture shift is a key factor for WBG adoption. At 800 V, the traction inverter operates with bus voltages that are very close, or even higher, than the rating limits of conventional silicon power devices, such as IGBTs.
SiC MOSFETs, rated at 1,200 V or higher with low on-resistance (RDS(on)) and fast-switching behavior, are suited for this application. In 2021, SiC inverters had a market share of less than 8% in global EV production, reaching 24% by 2026, according to market research firm Market Intelo. Analysts estimate that by 2030, SiC inverters will reach a 55% market share across EV production.
In January 2025, Wolfspeed Inc. introduced its Gen 4 SiC MOSFET platform, covering 750-V, 1,200-V, and 2,300-V voltage classes in discrete, module, and bare-die form. Compared with the previous version, Gen 4 technology reduces the specific on-resistance (Ron,sp) at high temperatures by up to 21% (with an even higher reduction at low temperatures) and provides improved turn-on performance with reduced ringing.
Built on this platform are the 1,200-V six-pack power modules (Figure 1), part of the automotive-qualified YM Six-Pack module line. These modules integrate a direct-cooled pin-fin baseplate and use sintered die-attach layers, copper-clip interconnects, and epoxy encapsulation to improve power-cycling capability. According to Wolfspeed, they deliver a 3× higher power-cycling capability at rated operating temperature than comparable competitor modules. The YM package size is compatible with existing IGBT inverter housings, simplifying platform migration.
Wolfspeed recently introduced its Gen 5 SiC MOSFET planar technology. Manufactured in Wolfspeed’s 200-mm fabs, the latest generation further reduces Ron,sp by up to 27% for 1,200-V devices, raising continuous junction temperature to 200°C for improved reliability.
STMicroelectronics provides 750-V and 1,200-V, automotive-qualified devices for 400-V and 800-V EV traction inverters, thanks to the introduction of the company’s Gen 4 SiC MOSFET technology. Gen 4 devices offer reduced RDS(on) (8.2 mΩ and 10.2–10.9 mΩ for the 750-V and 1,200-V classes, respectively) to cut conduction losses.
ST also announced the ongoing development of a higher-temperature-capable architecture to further reduce RDS(on) at high junction temperatures, meeting the requirements of air-cooled or passively cooled traction inverter designs.
Rohm Semiconductor introduced the TRCDRIVE pack, designed for xEV traction inverters. Built on Gen 4 SiC MOSFET technology, these 750-V and 1,200-V, two-in-one SiC molded modules feature higher power density, a compact layout that optimizes heat dissipation, and signal terminals supporting press-fit mounting (Figure 2).
Rohm also partnered with Schaeffler on a high-voltage inverter brick in mass production for a leading Chinese automaker. The brick integrates Rohm’s Gen 4 SiC MOSFET bare chips with a DC-link capacitor, a cooling solution, and a DC boost function. The design allows 800-V EVs to use a 400-V charging infrastructure. More recently, Rohm announced the availability of its Gen 5 SiC MOSFETs, targeting xEV traction inverters with a further reduction of RDS(on) at high temperatures.
Cambridge GaN Devices (CGD) has developed a 650-V ICeGaN device for automotive applications, including xEV traction inverters. While the device offers a lower blocking voltage than SiC counterparts, according to CGD, it can be paralleled without suffering imbalance or requiring a careful selection of components with similar characteristics.
The ICeGaN device integrates protection features, offering low RDS(on) (9 mΩ), reduced losses, and improved thermal management. CGD has also showcased a multilevel, 800-V inverter based on this device that can power electric motors to over 100-kW peak, 75-kW continuous power.
OBCs: SiC and GaN share the space
The OBC converts the AC grid power to the DC required by the main battery. It operates at lower power (typically 11 kW to 22 kW for passenger cars) than the traction inverter. SiC MOSFETs are currently the most common choice for OBCs, particularly for 800-V battery systems in which 1,200-V SiC devices offer wide operating margins and high reliability.
Rohm released a family of 750-V and 1,200-V SiC molded modules in the HSDIP20 package for xEV OBCs. The package integrates components for power-factor correction (PFC) and LLC conversion, including SiC MOSFETs, an insulating substrate, and decoupling elements. Available in four-in-one and six-in-one configurations, the modules reduce chip temperature by up to 38°C under a 25-W output load compared with discrete SiC MOSFETs.
Navitas Semiconductor announced the automotive qualification of its high-power GaNSafe Gen 4 ICs to both AEC-Q100 (integrated circuit) and AEC-Q101 (discrete transistor) standards (Figure 3). The GaNSafe family integrates control, gate drive, and sensing. It also offers short-circuit protection with a maximum latency of 350 ns, 2-kV ESD protection on all pins, programmable slew rate control, and elimination of the negative gate drive requirement. The devices are suited for OBCs and HV-LV DC/DC converters.
Navitas also introduced the first production-ready, 650-V bidirectional GaNFast ICs with IsoFast isolated gate drivers. This solution enables OBCs with a single-stage AC/DC topology that eliminates the conventional two-stage approach (with a separate PFC and DC/DC).
DC/DC converters and 48-V systems: GaN gains ground
GaN power devices are being adopted in DC/DC converters for EV applications. In EVs, DC/DC converters step down the main 400-V or 800-V battery bus to 12 V or 48 V for vehicle auxiliary loads. For example, Vitesco Technologies selected Infineon Technologies AG’s CoolGaN 650-V devices for its Generation 5+ DC/DC converter. The fast-switching capability of GaN at 650 V enables higher converter switching frequencies, which reduces the size of the magnetics and filtering capacitors.
Also, auxiliary vehicle systems, such as electric power steering pumps, cooling fans, HVAC compressors, and 48-V mild hybrid motor generators, operate at voltage levels at which 100-V- to 200-V-rated GaN devices are fully suitable today.
One example is Infineon’s automotive-grade GaN transistor family that is suitable for low-voltage subsystems, such as 48-V and auxiliary power rails in hybrid and full-electric vehicles. These CoolGaN 100-V G1 devices (Figure 4) are qualified to AEC-Q101.
SiC is also used in DC/DC converters, particularly for bidirectional designs operating from 800-V battery systems. The Rohm HSDIP20 molded modules mentioned in the OBC section are specified for both PFC and LLC DC/DC stages, making them suitable for OBC and DC/DC converter applications.
Final considerations
After reaching mature status as a semiconductor technology, the primary challenge for SiC has shifted to scaling up production volume and reducing costs. The wide adoption of SiC in the automotive industry has forced the transition from older, 150-mm to 200-mm wafers, with the setup of dedicated fabs. This shift significantly reduces the cost of single chips and increases the yield per wafer. Wolfspeed has advanced production by developing the industry’s first 300-mm, single-crystal SiC wafer.
In the past, GaN faced issues with automotive adoption due to a lack of long-term field-reliability data. As mentioned, several GaN devices have successfully achieved AEC-Q101 and AEC-Q100 qualifications. Moreover, several manufacturers, including Texas Instruments Inc., are claiming a failure-in-time rate for GaN devices below 1 (fewer than one failure per billion device-hours) over a targeted 10- or 15-year lifecycle.
Interestingly, GaN is also experiencing a 300-mm trend. Because GaN is typically grown on top of standard silicon substrates (GaN-on-Si), companies such as Infineon have scaled 300-mm GaN power wafer technology by using existing silicon manufacturing lines, lowering the device costs.
Imec also announced plans to manufacture 300-mm GaN wafers with several partners, including Aixtron, GlobalFoundries, KLA Corporation, Synopsys, and Veeco. The GaN program will focus first on using 300-mm Si(111) as a substrate for low-power applications, followed by high-power applications (650 V and above) using 300-mm semi-spec and CMOS-compatible QST engineered substrates from Qromis Inc.
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