GaN vs SiC: Which Semiconductor for Which EV Application?

Material Properties Comparison

Key Insight: GaN has higher electron mobility (lower Rdson), but SiC has much higher thermal conductivity. This makes SiC better for high-power density and high-temperature applications.

Application Selection Framework

By Voltage

< 200V: GaN wins clearly.

200V – 400V: GaN competitive, but SiC thermal advantage starts showing.

400V – 1200V: SiC wins (GaN limited to 650V in mainstream).

By Power Level

< 1 kW: GaN preferred (low dissipation).

1 kW – 7 kW: Both viable. GaN for PFC, SiC for DC-DC.

> 22 kW: SiC dominates due to thermal requirements and paralleling maturity.

Decision Table: EV Charging Applications

The Edrift Approach: Hybrid Design

We extract optimal performance by using GaN for the totem-pole PFC stage (high frequency, zero recovery) and SiC for the isolated DC-DC stage (bidirectional body diode, thermal advantage). This achieves >96% system efficiency.