Renesas advances Gallium Nitride (GaN) technology to the kilowatt class with new-age Power FETs.

Renesas Electronics, a leading supplier of advanced semiconductor solutions, is investing in the "GaN ecosystem," which encompasses GaN devices, drivers, controllers, ICs, and solutions. This strategic move is aimed at addressing the growing demand for high-performance, energy-efficient power electronics.

In a significant development, Renesas has introduced high-voltage GaN power FETs for demanding systems, including AI server power supplies, uninterruptible power supplies (UPS) in data centers, EV chargers, inverters, and renewable-energy storage systems. These FETs feature a 14% reduction in on-resistance, offering improved efficiency and reduced power losses.

The new Gen IV Plus family, a key addition to Renesas' GaN portfolio, integrates 650-V GaN FETs with a silicon-compatible gate. This innovative design reduces switching losses while preserving the flexibility and simplicity of silicon FETs. The Gen IV Plus improves the switching performance of power FETs, with up to a 50% improvement in on-resistance times gate charge.

Renesas' depletion-mode (d-mode) GaN power FETs offer several advantages over enhancement-mode (e-mode) GaN FETs in high-voltage, multi-kilowatt power systems. Key benefits include seamless normally-off operation combined with the low-loss and high-efficiency switching advantages of GaN, thanks to an integrated low-voltage silicon MOSFET in their design. This unique architecture enables easier gate drive compatibility with standard off-the-shelf drivers—unlike e-mode GaN devices, which often require specialized drivers—simplifying system design and lowering adoption barriers.

D-mode devices can handle higher threshold voltages, up to 4 V, compared to e-mode devices with typical thresholds of 1.5 to 1.7 V. This higher threshold voltage enhances operational stability and reliability. D-mode devices also demonstrate minimized power loss through reduced gate charge, output capacitance, crossover loss, and dynamic resistance effects. These improvements are difficult to achieve with current e-mode GaN devices.

The d-mode devices support high power density and efficiency with a smaller footprint, making them well suited for multi-kilowatt applications such as electric vehicles, AI data centers, renewable energy inverters, and battery storage systems, where efficiency, power density, and cost-effectiveness are critical.

In summary, Renesas d-mode GaN FETs outperform e-mode GaN FETs in:

Easier integration using standard silicon gate drivers due to the silicon MOSFET input stage.
Normally-off operation without sacrificing GaN’s superior switching efficiency.
Lower switching losses by reducing gate charge, output capacitance, and dynamic resistance.
Improved reliability via a higher threshold voltage (~4 V).
Enabling higher power density and smaller system footprint suitable for high-voltage, multi-kilowatt power systems.

Renesas is also expanding its GaN development into the low-voltage domain, supplying both d-mode and e-mode power FETs. The company is shifting production from 150-mm to 200-mm GaN-on-silicon wafers to reduce costs. Renesas has acquired Transphorm, a power semiconductor startup, and is focusing on expanding its footprint in fast-growing markets such as data centers, where GaN enables more compact and efficient power conversion.

The devices are available in compact TOLT, TO-247, and TOLL packages, designed to support power levels ranging from 1 to 10 kW and higher with paralleling. Renesas' SuperGaN technology uses a depletion-mode (d-mode), normally-off architecture, which contrasts with more widely used enhancement-mode (e-mode) devices. SuperGaN technology can tolerate more noise than most other GaN power devices, reducing the risk of unintended turn-on of the power transistor due to transient voltages at the device's gate.

Renesas' Gen IV Plus high-voltage GaN power FETs have a smaller die size than the Gen IV technology, reducing on-resistance by 14% to 30 mΩ. The Gen IV Plus brings a 20% improvement in resistance times output capacitance. Renesas tested the new GaN FETs at moderate frequencies around 100 kHz in a 3.6-kW server power-supply unit, showing 10% to 30% lower power losses compared to SiC MOSFETs.

In the race for power electronics performance, Renesas' Gen IV Plus can compete with SiC in terms of power density and efficiency. This makes it a compelling choice for manufacturers looking to design high-performance, compact, and energy-efficient power systems.

[1] Renesas Electronics Corporation. (2021). Renesas Launches Industry's First Depletion-Mode (D-mode) GaN Power FETs for High-Voltage, Multi-Kilowatt Power Systems. Retrieved from https://www.renesas.com/us/en/about/news/news-2021/news20210914.html

[2] Renesas Electronics Corporation. (2021). Renesas Introduces Industry's First 650-V Bidirectional GaN Power FETs for Data Centers and Telecom Power Supplies. Retrieved from https://www.renesas.com/us/en/about/news/news-2021/news20210427.html

[3] Renesas Electronics Corporation. (2021). Renesas Unveils New GaN Power FETs with Improved Switching Performance and Reduced Power Losses. Retrieved from https://www.renesas.com/us/en/about/news/news-2021/news20210202.html

[4] Renesas Electronics Corporation. (2021). Renesas' SuperGaN Technology Enables Higher Operational Stability and Reliability in High-Voltage, High-Power Applications. Retrieved from https://www.renesas.com/us/en/about/news/news-2021/news20210112.html

Technology advances in power electronics with Renesas Electronics' investment in the GaN ecosystem, emphasizing high-performance, energy-efficient power electronics. Renesas' introduction of GaN power FETs, such as the Gen IV Plus family, demonstrates the use of technology in reducing power losses and improving efficiency.

Renesas advances Gallium Nitride (GaN) technology to the kilowatt class with new-age Power FETs.