650V Gallium Nitride Integrated Circuit for Electric Vehicle Powertrains

Automotive powertrain design relies on efficient power conversion to optimize energy usage and system weight. To address these parameters, Cambridge GaN Devices (CGD) has developed a 650V gallium nitride (GaN) integrated circuit designed specifically for electric vehicle (EV) inverter applications.

Parallel Operation and Circuit Balancing
Implementing GaN integrated circuits in parallel configurations for powertrain systems typically requires precise device matching to maintain operational balance. The architecture developed by CGD incorporates an internal interface that intrinsically balances the operation of multiple devices. This configuration eliminates the need to select devices with identical performance characteristics and removes the requirement for external balancing components, thereby reducing circuit complexity within the inverter.

Thermal Management and Switching Frequency
The 650V device features a low on-resistance of 9mΩ, which limits conduction losses across the electric vehicle’s powertrain. Lower power dissipation directly decreases the thermal load, reducing the physical requirements for external thermal management hardware. Additionally, the device is capable of high-frequency switching operations, which allows for the utilization of smaller passive components. This mechanism contributes to the overall downsizing and weight reduction of the propulsion system.

Gate Driver Interface and Diagnostics
The integrated circuit simplifies the connection with external gate driver components in the inverter. It incorporates an auxiliary transistor within the interface that filters parasitic noise generated from the gate driver loops, establishing built-in immunity to electromagnetic interference. For system diagnostics and control, the interface includes integrated temperature sensing, providing continuous thermal data to the system controller to monitor and maintain operational stability.

High-Voltage Inverter Prototyping
The component operates within high-voltage electrification frameworks. CGD has utilized the device to demonstrate a multi-level 800Vdc inverter capable of driving electric motors at 75 kW continuous power and exceeding 100 kW peak power. Manufacturing and supply chain operations for the integrated circuit are supported through a partnership with semiconductor manufacturer GlobalFoundries (GF), targeting automotive OEMs and Tier One suppliers.

Additional Context: This section details technical specifications and competitive benchmarking not included in the original product announcement.
In the automotive power electronics sector, 650V GaN devices compete directly with Silicon Carbide (SiC) MOSFETs and traditional Silicon Insulated-Gate Bipolar Transistors (IGBTs) for 400V and 800V bus architectures. While SiC currently has high adoption in the 800V inverter market due to component voltage ratings reaching up to 1200V, 650V GaN devices configured in multi-level topologies offer an alternative by supporting higher switching frequencies with lower switching losses. Standard discrete GaN high-electron-mobility transistors (HEMTs) often present engineering challenges related to gate overvoltage and dynamic on-resistance under continuous switching. By integrating the gate drive and protection circuitry directly onto the GaN die, integrated GaN solutions mitigate parasitic gate loop inductance, ensuring more stable operation at high dV/dt slew rates compared to discrete semiconductor alternatives.

Edited by an industrial journalist, Lekshman Ramdas, with AI assistance.

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