ROHM has developed an isolated gate driver IC – the BM6GD11BFJ-LB. It is designed specifically for driving 600V-class high-voltage GaN HEMTs. When combined with GaN devices, this driver enables stable operation under high-frequency, high-speed switching conditions – contributing to greater miniaturization and efficiency in high-current applications such as motors and server power supplies.
As global energy consumption continues to grow, energy-saving initiatives have become a shared global priority. Motors and power supplies alone are estimated to account for approx. 97% of the world’s total electricity consumption. Achieving higher efficiency in these systems is increasingly dependent on utilizing wide bandgap devices such as SiC and GaN to control and convert electricity more efficiently.
Leveraging expertise in developing isolated gate driver ICs for silicon semiconductors and SiC devices, ROHM has introduced this new IC as the first in a series of isolated gate driver solutions optimized for GaN devices. Safe signal transmission is achieved by isolating the device from the control circuitry during switching operations that involve rapid voltage rise and fall cycles.
The BM6GD11BFJ-LB utilizes proprietary on-chip isolation technology to reduce parasitic capacitance, enabling high-frequency operation up to 2MHz. This maximizes the high-frequency switching capabilities of GaN devices. This contributes not only to greater energy efficiency and performance in applications but also reduces mounting area by minimizing the size of peripheral components.
At the same time, CMTI (Common-Mode Transient Immunity – an indicator of noise tolerance in noise isolated gate driver ICs) has been increased to 150V/ns – 1.5 times higher than conventional products – preventing malfunctions caused by the high slew rates typical of GaN HEMT switching. The minimum pulse width has also been reduced to just 65ns, 33% less than conventional products. These performance improvements allow for stable, reliable operation at higher frequencies while minimizing power loss through better duty cycle control.
With a gate drive voltage range of 4.5V to 6.0V and an isolation voltage of 2500Vrms, the BM6GD11BFJ-LB is designed to fully support a wide range of high-voltage GaN devices, including ROHM’s newly added 650V EcoGaN HEMT. The industry-leading low output-side current consumption of 0.5mA (Max) also reduces standby power, improving overall system efficiency.
The BM6GD11BFJ-LB is now available. It is offered through online distributors such as DigiKey and Mouser. The sample price is $4.0/unit (excluding tax).
Going forward, ROHM plans to offer gate driver ICs for GaN device control together with GaN device products, supporting simpler application design.
EcoGaN is a trademark or registered trademark of ROHM Co., Ltd.
Application Examples
Industrial Equipment: Power supplies for PV inverters, ESS (Energy Storage Systems), communication base stations, servers, and industrial motors
Consumer Devices: White goods, AC adapters (USB chargers), PCs, TVs, refrigerators, Air Conditioners
Terminology
Common-Mode Transient Immunity (CMTI)
A key parameter of isolated gate drivers, CMTI refers to the driver’s ability to withstand rapid voltage changes that occur over very short durations. This is especially important when driving high slew rate devices such as GaN HEMTs, where rapid voltage transitions are common. A gate driver with high CMTI can prevent device damage while reducing the risk of circuit shorts.
