ST widens GaN range with additional 45W and 150W devices
The MasterGaN range of GaN devices from STMicroelectronics has been expanded with the addition of the MasterGaN3 and MasterGaN5. Supplied in integrated power packages, they are designed for applications up to 45W and 150W, respectively.
They join the existing MasterGaN1, MasterGaN2, and MasterGaN4, which target applications from 65 to 400W. the MasterGaN range of devices and drivers are intended for switched mode power supplies, chargers, adapters, high voltage power-factor correction (PFC), and DC/DC converters.
ST said that its MasterGaN concept simplifies migrating from ordinary silicon MOSFETs to GaN wide-bandgap power technology. The devices integrate two 650V power transistors with optimised high voltage gate drivers and associated safety and protection circuitry, eliminating gate-driver and circuit-layout design challenges. Combined with the higher switching frequencies possible with GaN transistors, they enable power supplies that are up to 80 per cent smaller than silicon-based designs. They are also as well robust and reliable, said ST.
The GaN power transistors of MasterGaN3 devices have asymmetrical on-resistance (RDSon) of 225 and 450 mOhm, making them suited to soft switching and active rectification converters. In MasterGaN5 both transistors have 450 mOhm RDSon for use in topologies such as LLC-resonant and active clamp flyback.
In common with other MasterGaN family members, both devices have inputs compatible with logic signals from 3.3 to 15V, 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 under-voltage lockout (UVLO), gate driver interlocks, over-temperature protection and a shutdown pin.
Each MasterGaN device is supported with 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. There is an adjustable dead-time generator, as well as connections for the user to apply a separate input signal or PWM signal, add an external bootstrap diode to help with capacitive loads, and insert a low-side shunt resistor for peak-current-mode topologies.
The MasterGaN3 and MasterGaN5 are housed in a 9.0 x 9.0mm GQFN package optimised for high voltage applications with 2.0mm creepage distance between high voltage and low voltage pads. Both are in production now.