ST Expands GaN Gate Drivers for Power Conversion, Efficiency

Gallium nitride (GaN) transistors offer faster switching speeds, higher efficiency, and better power density than traditional silicon MOSFETs. However, unlocking their full potential, especially in high-voltage, high-frequency designs, demands specialized gate drivers that can manage speed, safety, and timing precision. Without the right gate driver, engineers face challenges like shoot-through, timing mismatches, and degraded performance in demanding applications.

STMicroelectronics has introduced its STDRIVEG610 and STDRIVEG611 gate drivers targeting two key uses in GaN power design: high-frequency, soft-switching converters and hard-switching motor control. With tight timing control and minimal external components, the STDRIVE610 and STDRIVE611 give engineers a new tool for deploying GaN across multiple applications, ranging from household appliances to precise motor control.

STMicroelectronics expands its STDRIVE600 series with the STDrive610 and STDrive611. Image used courtesy of STMicroelectronics

Specific Gate Drivers for High-Speed GaN Designs

STMicroelectronics’ new half-bridge gate drivers have been engineered to drive 600 V enhancement-mode GaN FETs with tight control and minimal external circuitry. While both devices share a compact 4 mm x 5 mm QFN footprint and core features like low propagation delay, interlocking, and high dv/dt immunity, each is tuned for distinct engineering use cases. The G610 is optimized for high-frequency, soft-switching power conversion, while the G611 adds rugged protections for hard-switching, motor-control environments.

STDRIVEG610: Designed for High-Speed Power Conversion

The STDRIVEG610 targets power designers working on high-frequency, low-loss converter topologies, such as LLC resonant converters, active clamp flyback designs, and totem-pole PFC circuits, where accurate timing and low conduction losses are needed. These are the workhorses of modern AC/DC adapters, battery chargers, USB-PD solutions, and energy-efficient data center power supplies.

The block diagram for the STRDrive610. Image used courtesy of STMicroelectronics

The STG610 features an ultra-fast 300 ns startup time, which is essential in soft-switching circuits that rely on tightly timed bursts. The STG610 also integrates 6 V high-side and low-side linear regulators that can deliver high current, removing the need for external LDOs and simplifying PCB layout. The device supports switching frequencies over 1 MHz and features a matched propagation delay of 45 ns, minimizing timing skew between legs and enhancing overall efficiency.

The driver also includes a standby mode to reduce consumption during burst operation, which is critical in meeting energy regulations for standby power. With its wide logic input range (3.3 V to 20 V), engineers can directly interface it with a variety of controllers without additional level shifting. For safety and reliability, the device includes under-voltage lockout and ±200 V/ns dv/dt immunity, making it resilient against voltage spikes and transients.

STDRIVEG611: Built for Rugged Motion and Industrial Applications

The STDRIVEG611 is aimed squarely at engineers developing motor drives and motion-control systems where electrical noise, load variability, and system robustness are significant concerns. It’s optimized for hard-switching environments and includes advanced protection features such as high-side UVLO, a comparator-based overcurrent detector, and a Smart Shutdown (SmartSD) mechanism that disables the output during an overcurrent fault.

Block diagram for the STRDrive611. Image used courtesy of STMicroelectronics

This makes the G611 particularly suitable for demanding applications such as industrial servo drives, HVAC compressors, washing machines, pumps, and e-bike motor controllers. In these systems, sudden load shifts and noisy switching environments can wreak havoc on less robust gate drivers. With the G611’s fast 5µs startup time, matched delay paths, and integrated bootstrap diode, engineers can maintain control fidelity and avoid shoot-through conditions.

Its separated sink and source drive paths (2.4A sink / 1.0A source) provide tailored gate control for rapid turn-on and turn-off, reducing switching losses and EMI. And like the G610, it also supports switching frequencies above 1 MHz and offers ±200 V/ns dv/dt immunity, essential in fast-switching motor control designs. A fault pin enables real-time reporting of thermal and voltage anomalies, helping designers implement safety mechanisms at the system level.

The G611 also features a standby mode that was designed to reduce idle power consumption, while also offering a Kelvin ground connection for accurate current sensing, making it a practical choice for designs requiring precise motor feedback or current protection.

Design and Prototyping Tools

Both drivers offer design features to reduce component count and board complexity, including built-in bootstrap diodes, separate sink/source drive paths (2.4 A sink / 1.0 A source), and matched 45 ns propagation delays. Their strong dv/dt immunity of ±200 V/ns ensures reliable operation in noisy environments.

For quick evaluation, ST provides ready-to-use development boards, EVLSTDRIVEG610Q and EVLSTDRIVEG611, each featuring the corresponding driver paired with 600 V SGT120R65AL GaN HEMTs, that enable engineers to validate switching performance and protection features in practical setups.

The EVLSTDRIVEG610Q (left) and EVLSTDRIVEG611 (right). Images used courtesy of STMicroelectronics

By delivering tailored gate driving solutions for two of the most common yet demanding GaN use cases, precision power conversion and resilient motor control, STMicroelectronics offers engineers higher efficiency, reduced board space, and simplified protection management.