Integrated GaN Half-Bridge Targets Compact Power Converters

Higher switching frequencies and shrinking form factors are pushing designers toward gallium-nitride devices in power conversion stages. Addressing these constraints across consumer and industrial supplies, STMicroelectronics introduced the MasterGaN6 integrated half-bridge power IC.

Moving GaN integration beyond discrete stages
The MasterGaN6 belongs to the second generation of the MasterGaN family and combines a GaN power transistor with an updated BCD driver in a single power-system-in-package device. The transistor features 140 mΩ RDS(on) and supports currents up to 10 A, covering adapters, chargers, industrial lighting power supplies, and DC-to-AC solar micro-inverters.

Dedicated pins for fault indication and standby operation extend system supervision capability, allowing power supplies to signal abnormal conditions and enter low-consumption states. Integrated LDO regulators and a bootstrap diode reduce the number of external components required around the switching stage, simplifying PCB routing in compact converter designs.

High-frequency operation and low-load efficiency
The driver stage is designed for short minimum on-time and low propagation delay, enabling high switching frequency operation. Higher frequency allows smaller magnetics and passive components, reducing overall converter size — a typical requirement in dense consumer adapters and distributed industrial power nodes.

The device also incorporates fast wake-up timing to improve burst-mode behavior at light load. This operating mode is commonly used to maintain efficiency in standby conditions, relevant for energy-regulated consumer power supplies and distributed nodes in a digital supply chain of connected equipment.

Built-in protection and supported topologies
Protection functions include cross-conduction prevention, thermal shutdown, and undervoltage lockout. Integrating these protections within the half-bridge removes discrete monitoring circuitry and helps reduce bill of materials.

The half-bridge configuration supports multiple converter architectures, including active-clamp flyback (ACF), resonant LLC, inverse buck converters, and power-factor-correction (PFC) stages. This allows the same IC to be used across a range of AC-DC and DC-AC designs, from compact USB-PD adapters to photovoltaic micro-inverters.

Evaluation and simulation support
For development and thermal verification, STMicroelectronics released the EVLMG6 evaluation board and added a MasterGaN6 model to the eDesignSuite PCB Thermal Simulator, enabling designers to analyze heat distribution and switching performance during early design stages.

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