In recent years, due to the growing demand for server systems in response to the increasing number of IoT devices, improvements in energy conversion efficiency and size reduction have become important societal issues requiring new advancements in the power device sector.
In addition to mass-producing industry-leading SiC devices and a wide variety of multi-function silicon devices, ROHM has developed GaN devices that offer superior high-frequency operation in the medium-voltage range. The development of technology that increases the gate-source voltage rating allows ROHM to offer a broader range of power solutions for a wide variety of applications.
Because GaN devices offer improved switching characteristics and lower conduction resistance than silicon devices, they are expected to contribute to reduced power consumption and further miniaturization of switched-mode power supplies used in base stations and data centers. However, some drawbacks—including low nominal gate-source voltage and overshoot voltages that exceed maximum capacity during switching—pose significant challenges to device reliability.
In response to these challenges, ROHM has succeeded in increasing the nominal gate-source voltage from the typical 6 V to 8 V using an original design. This allows for improved design margin and increased reliability in power supply circuits using GaN devices that require high efficiency. In addition to maximizing device performance with low parasitic inductance, we are also developing a custom package that simplifies assembly and offers excellent heat dissipation, enabling easy replacement of existing silicon devices while also simplifying handling during the assembly process.
In the future, ROHM will accelerate the development of GaN devices based on this technology, with a sample shipment planned for September 2021.
(Fig. 2+ 3)
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 and wireless charging circuits for portable devices
(Fig. 4)
