GaN gate drivers with integrated protection

STMicroelectronics recently unveiled two half-bridge GaN gate drivers tailored for high-speed switching in power conversion and motion-control systems. These innovative devices are designed to facilitate more compact and efficient designs by incorporating essential control and protection functions into a single package. This announcement is particularly significant for eeNews Europe readers engaged in industrial drives or power stages, as it underscores a broader trend towards tighter integration centered around wide bandgap devices, where control accuracy and protection are becoming increasingly crucial.

The STDRIVEG212 and STDRIVEG612 are specifically engineered to drive enhancement-mode GaN HEMTs with regulated 5V gate signals. They are capable of supporting high-side operation up to 220V and 600V, respectively, making them ideal for applications such as motor drives and high-frequency converters. These devices feature integrated high-side and low-side LDO regulators, a bootstrap diode, and various protection mechanisms including under-voltage lock-out. In the event of overcurrent, an embedded comparator disables both switches, while a SmartSD shutdown mechanism ensures the system remains off for a sufficient duration to manage thermal stress. Furthermore, a fault pin consolidates reporting for overcurrent, overtemperature, and UVLO events.

Enhanced Performance and Tuning Capabilities

One of the key highlights of these GaN gate drivers is their ability to support fast switching, boasting a propagation delay of just 50ns and closely matched timing between high-side and low-side channels. With ±200V/ns dV/dt immunity and a high-side startup time of 5µs, these drivers enable higher switching frequencies and potentially faster motor speeds. Designers can independently tune turn-on and turn-off impedance in the output stage, allowing for precise control over switching transients without the need for additional external components like turn-off diodes. This not only simplifies the bill of materials but also streamlines the layout. Additionally, the separate sink and source paths, with up to 1.8A sink and 0.8A source capability, further enhance switching optimization.

Moreover, the devices are equipped with 20V-tolerant logic inputs and a dedicated shutdown pin for low-power standby operation. Packaged in a compact 4mm × 5mm QFN form factor, they are rated for operation in a wide temperature range from -40°C to 125°C. To assist developers in evaluating their performance, an evaluation board supporting both variants is also available.