Subaru to Evaluate Onsemi Platform Offering 4X EV Inverter Power Density

Subaru has partnered with semiconductor maker Onsemi to evaluate a new power electronics architecture designed to quadruple power density in electric vehicle traction inverters.

Under the collaboration, the Japanese automaker will receive early access to engineering samples, simulation models and technical expertise later this year to test the system across its future electrified vehicle architectures.

Wafer-level packaging for vehicle drives

Named the Embedded Power Platform, the system uses the silicon wafer itself as the package base. This setup combines silicon, silicon carbide and gallium nitride components. It also integrates field-effect transistors, gate drivers and system controllers inside a single module.

Building components directly on 12-inch wafer production lines eliminates multiple assembly steps. It also cuts parasitic inductance. Lower inductance reduces electrical losses and lets power switches run at higher frequencies without excessive heat.

Onsemi claims the architecture cuts inverter power losses by up to 15 per cent and shrinks the footprint up to fourfold. Subaru has not committed the hardware to a specific production model yet. Still, the evaluation gives the carmaker a direct look at multi-voltage powertrain integration.

Standardising power across vehicle lines

Modular power electronics offer Japanese carmakers a way to cut engineering overhead as they chase global battery-electric rivals. Engineers can scale one base architecture across compact cars, crossovers and commercial platforms instead of designing custom inverters for each vehicle class.

This strategy shifts component integration risk from the vehicle assembly line to the chip fabrication plant. Automakers get smaller, lighter drive units. However, they face greater dependence on single-source packaging methods that cannot be swapped quickly during supply shortages.

Industrial and data centre crossover

Beyond passenger cars, the platform scales into industrial machinery and artificial intelligence data centre power racks. In non-automotive setups, Onsemi claims power density jumps by three to five times. That reduction cuts hardware development timelines to four months in select industrial cases.

Japanese manufacturers spent the past two years consolidating electric powertrain supply chains to protect operating margins as domestic hybrid sales peak. Subaru previously committed to expanding its electrified lineup through joint projects with Toyota, focusing on shared platform costs and joint battery procurement.

Initial engineering samples of the platform will ship to Subaru and select artificial intelligence hardware partners before the end of 2026.