Solving the gate breakdown voltage problem of GaN devices

ROHM has developed what it claims is the industry’s highest (8V) gate breakdown voltage (rated gate-source voltage) technology for 150V GaN HEMT devices – optimised for power supply circuits in industrial and communication equipment.

With mass-producing industry-leading SiC devices and a mixture of feature-rich silicon devices, the company has developed GaN devices providing superior high-frequency operation in the medium-voltage range. Developing technology that increases the rated gate-source voltage allows it to propose a broader range of power solutions for many applications.

As GaN devices offer enhanced switching characteristics and lower ON resistance than silicon devices, they are anticipated to contribute to lower power consumption and greater miniaturisation of switching power supplies employed in base stations and data centres. However, drawbacks that incorporate low rated gate-source voltage and overshoot voltage exceeding the max rating through switching pose major hurdles to device reliability.

In response, the company has succeeded in raising the rated gate-source voltage from the typical 6V to 8V, employing an original structure. This makes it feasible to improve the design margin and advance the reliability of power supply circuits utilising GaN devices that need high efficiency. In addition to maximising device performance with low parasitic inductance, they are also developing a dedicated package that aids mounting and provides exceptional heat dissipation, allowing easy replacement of existing silicon devices while simplifying handling throughout the mounting process.

Typical application examples include 48V input buck converter circuits for data centres and base stations; boost converter circuits for the power amplifier block of base stations; Class D audio amplifiers; and LiDAR drive circuits, wireless charging circuits for portable devices.