SiC vs GaN: Wide Bandgap Semiconductors for Power Electronics

SiC vs GaN: Wide Bandgap Semiconductors for Power Electronics

Silicon carbide (SiC) and gallium nitride (GaN) are pushing silicon out of power electronics. They switch faster, hold off higher voltages, and waste less energy as heat. Here's when we pick which, what we order, and the sourcing reality.

SiC vs GaN at a Glance

When to Choose SiC

SiC dominates high-voltage, high-power applications. Above 650V, GaN drops out — SiC gets the socket.

• EV traction inverters — Tesla, BYD, and others use SiC MOSFETs for 400V/800V systems
• Solar inverters — 1500V DC systems benefit from SiC's low switching losses
• Industrial motor drives — Reduced heatsink size, higher efficiency
• Power supplies above 3kW — Server PSUs, EV chargers

Popular SiC MOSFETs:

• Wolfspeed C3M0065090D (900V, 65mΩ)
• STMicroelectronics SCTW100N65G2AG (650V, 100mΩ)
• ROHM SCT3080KL (1200V, 80mΩ)

When to Choose GaN

GaN excels in high-frequency, medium-power applications. We've seen MHz switching shrink magnetics in practice — that's GaN's payoff.

• USB-C PD chargers — GaN enables 65W chargers the size of a matchbox
• Data center power — 48V to 1V conversion with >95% efficiency
• LiDAR — GaN's fast switching enables high-resolution pulses
• RF power amplifiers — 5G base stations, satellite comms
• Audio amplifiers — Class-D with lower distortion

Popular GaN FETs:

• Navitas NV6117 (650V, integrated driver)
• GaN Systems GS66508B (650V, 30A)
• EPC EPC2045 (100V, eGaN)

Chinese SiC/GaN Manufacturers

• BASiC Semiconductor — 650V-1700V SiC MOSFETs and diodes
• Sanan IC — GaN-on-SiC RF and power devices
• Innoscience — 650V GaN-on-Si E-mode HEMTs, mass production
• CETC 55 — SiC MOSFETs and SBDs for military/automotive

Sourcing Reality

Both SiC and GaN are supply-constrained — it shows in every quote.

• SiC substrates are mostly from Wolfspeed (US) and II-VI/Coherent — capacity is tight
• GaN-on-Si is easier to manufacture but the market is dominated by a few players
• Lead times of 16-30 weeks are common for SiC MOSFETs
• Prices are dropping 10-15% per year as manufacturing scales

References

• TI Power Management Guides
• IEEE Power Electronics