STMicro adds 45-W and 150-W MasterGaN integrated half-bridge drivers

STMicroelectronics has expanded its family of MasterGaN gallium-nitride (GaN) devices with the newly released MasterGaN3 and MasterGaN5 integrated power packages for applications up to 45 W and 150 W, respectively. The MasterGaN3 and MasterGaN5 600-V half-bridge drivers with two enhancement mode GaN HEMTs join the existing MasterGaN1, MasterGaN2, and MasterGaN4 series, which target applications from 65 W to 400 W.

Designed to simplify the transition from silicon mosfets to GaN wide-bandgap (WBG) power technology, the devices integrate two 650-V power transistors with optimized high-voltage gate drivers and associated safety and protection circuitry, which eliminates gate-driver and circuit-layout design challenges, said STMicroelectronics. They can be used in switched-mode power supplies, chargers, adapters, high-voltage power-factor correction (PFC), and DC/DC converters.

In addition, combined with the higher switching frequencies possible with GaN transistors, these integrated devices enable power supplies that are up to 80% smaller than silicon-based designs, said the company.

The GaN power transistors used in the MasterGaN3 devices feature asymmetrical on-resistance (Rds(on)) of 225 mΩ and 450 mΩ, making these devices suited to soft-switching and active-rectification converters. In MasterGaN5 both transistors have 450 mΩ Rds(on) for use in topologies such as LLC-resonant and active clamp flyback.

MasterGaN5 block diagram. (Source: STMicroelectronics)

Like other MasterGaN series, these devices offer inputs compatible with logic signals from 3.3 V to 15 V, which simplifies connection of a host DSP, FPGA, or microcontroller, and external devices such as Hall sensors. They also integrate protection including low-side and high-side undervoltage lockout (UVLO), gate-driver interlocks, over-temperature protection, and a shutdown pin. (The MasterGaN series was a runner-up in Electronic Products’ 2020 Product of the Year Awards.)

Each MasterGaN device offers a dedicated prototype board to help designers jump-start new power-supply projects. The EVALMASTERGAN3 and EVALMASTERGAN5 boards contain circuitry to generate single-ended or complementary driving signals. Other features include an adjustable dead-time generator as well as connections to apply a separate input signal or PWM signal, add an external bootstrap diode to help with capacitive loads, and include a low-side shunt Resistor for peak-current-mode topologies.

Housed in a 9 × 9-mm GQFN package optimized for high-voltage applications with 2-mm creepage distance between high-voltage and low-voltage pads, the MasterGaN3 and MasterGaN5 devices are in production now, priced from $6.08 and $5.77, respectively, for orders of 1,000 pieces.

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