High 8V gate breakdown voltage for 150V GaN HEMT

In recent years, due to the rising demand for server systems in response to the growing number of IoT devices, improving power conversion efficiency and reducing size have become important social issues that require further advancements in the power device sector.

Along with mass-producing industry-leading SiC devices and a variety of feature-rich silicon devices, ROHM has developed GaN devices featuring superior high frequency operation in the medium voltage range. Cultivating technology that increases the rated gate-source voltage allows ROHM to propose a wider range of power solutions for a variety of applications.

As GaN devices provide improved switching characteristics and lower ON resistance than silicon devices, they are expected to contribute to lower power consumption and greater miniaturisation of switching power supplies used in base stations and data centers. However, drawbacks that include low rated gate-source voltage and overshoot voltage exceeding the max. rating during switching pose major challenges to device reliability.

In response, ROHM succeeded in raising the rated gate-source voltage from the typical six to eight volts using an original structure. This makes it possible to both improve the design margin and increase the reliability of power supply circuits using GaN devices that require high efficiency.

In addition to maximising device performance with low parasitic inductance, we are also developing a dedicated package that facilitates mounting and delivers excellent heat dissipation, enabling easy replacement of existing silicon devices while simplifying handling during the mounting process.

Going forward, ROHM will accelerate the development of GaN devices based on this technology, with sample shipment planned for September 2021.

Application examples

• 48V input buck converter circuits for data centers and base stations.
• Boost converter circuits for the power amplifier block of base stations.
• Class D audio amplifiers.
• LiDAR drive circuits, wireless charging circuits for portable devices.