ROHM SiC Inside BMW's Neue Klasse: What Silicon Carbide Actually Carries in an 800V Drive

Bottom line: ROHM confirmed its SiC MOSFETs are in BMW’s Neue Klasse (Gen 6) electric powertrain. The Gen 6 inverter sits inside the motor housing on an 800 V + SiC architecture. Versus Gen 5, BMW estimates about 40% lower energy losses and roughly 20% better vehicle efficiency. ROHM did not name the device family, voltage class, or Tier-1 module builder—but the direction is clear: if you want an efficient high-voltage EV platform, silicon carbide is the battlefield.

Deep dive: 400 V → 800 V / SiC · e-powertrain & battery cost

Where does the next 800 V production bottleneck hit first—SiC wafers, power-module packaging, or OEM inverter lines?

Bottom line: In mid-September 2026, ROHM Semiconductor said its SiC MOSFETs are used in the electric powertrain electronics of BMW’s Neue Klasse (Gen 6) platform. Charged EVs summarized the story on 24 September. This is not a vague “evaluation sample” headline; it lands on the efficiency ledger of an 800 V integrated inverter. Keep the caveats: ROHM disclosed neither the MOSFET family nor the voltage class, and did not name the Tier-1 that builds the power electronics. BMW’s Gen 5 → Gen 6 deltas are OEM estimates, and SiC is one lever among several.

What happened

• Supply confirmation: ROHM SiC dies are in Neue Klasse traction power electronics (coverage from about 2026-09-17).
• Architecture: Gen 6 inverter is integrated into the e-motor housing, runs on 800 V, and lists SiC among its efficiency measures.
• BMW vs Gen 5 (OEM estimates): ~40% lower energy losses, ~20% lower cost, ~10% lower weight, ~20% better vehicle efficiency; about 30% faster charging and ~30% more range.
• Manufacturing: Plant Steyr began series production of Neue Klasse e-drives, building inverters in a clean-room environment in-house.

Engineering note: On an 800 V DC bus, SiC conduction and switching losses typically stay below those of a silicon IGBT at the same class. Avoided losses show up as more range at a fixed pack size, or as thermal headroom for harder DC charging. ROHM’s fifth-generation EcoSiC claims about 30% lower on-resistance versus Gen 4 at 175 °C junction temperature for equal breakdown voltage and die size—that is a device-level figure, not a one-to-one map onto BMW’s ~20% vehicle-efficiency claim.

Four engineering takeaways

1. Why 800 V + SiC instead of simply packing more cells?
Raise voltage at constant power and current falls, which eases I²R loss and conductor cross-section. The transistor must then survive higher dv/dt and thermal shock. Wide-bandgap SiC keeps high-voltage switching losses manageable—the same physics covered in the “400 V → 800 V” explainer.

2. Inverter-in-housing couples density with EMI and cooling risk
Integration shortens DC and AC paths and helps power density and cost, but it also packs the module, coolant channels, and noise coupling into one mechanical volume. Steyr’s clean-room inverter line means BMW owns that risk envelope instead of treating the inverter as a fully opaque purchased brick.

3. The supply question shifts from “any SiC?” to “whose SiC is on the OEM bill of materials?”
ROHM already publicized long-term SiC ties (including a Vitesco agreement valued at more than $1 billion through 2030, plus UAES and Schaeffler HV brick work). Naming Neue Klasse puts a European premium Gen 6 platform on the public scoreboard. Still missing: exact MOSFET series, dies per vehicle, and who packages the module.

4. Close the loop with e-powertrain cost, not die price alone
SiC wafers and modules look expensive until you re-open the system bill: cooler size, copper, charge time, and usable range. That is why “cheap dumb BEV” rarely survives engineering review—the pack, SiC, packaging yield, and inverter line sit on one cost curve.

Open questions

• Device family, voltage class, die count, and Tier-1 remain undisclosed by ROHM.
• The 40% / 20% / 10% / 30% figures are BMW estimates versus Gen 5; production test conditions still need independent cross-checks.
• No public split of how much SiC vs motor design, gear ratio, thermal design, or software efficiency contributes.

@vkinng videos

• Why EVs jump from 400 V to 800 V — SiC is the real heart
• Why OEMs will not ship a “dumb cheap BEV” — e-powertrain & battery cost floor

Poll: For the next mass-production 800 V platform, does the bottleneck hit SiC wafer capacity, power-module packaging, or OEM inverter lines first?

Sources: Charged EVs (2026-09-24); Semiconductor Today / ROHM (~2026-09-17); BMW Group Plant Steyr Gen 6 e-drive production notes.
Published for The Automation Core · YouTube @vkinng