50 W GaN converter enables high-efficiency power designs
The STMicroelectronics VIPerGaN50 simplifies building single-switch flyback converters up to 50 W and integrates a 650-V gallium-nitride (GaN) power transistor for superior energy efficiency and miniaturization. The high electron mobility of GaN enables tolerance of high switching frequencies. Consequently GaN devices can handle greater loads while suffering far fewer losses, enabling the creation of supplies that can output more power while shrinking their overall footprint.
With its single-switch topology and high integration, including current-sensing and protection circuitry also built-in, the VIPerGaN50 comes in a compact and low-cost 5- x 6-mm package. The speed of the integrated GaN transistor allows a high switching frequency with a small and lightweight flyback transformer. Minimal additional external components are needed to design an advanced, high-efficiency switched-mode power supply (SMPS).
The VIPerGaN50 helps designers leverage GaN wide-bandgap technology to meet increasingly stringent eco-design codes that target global energy savings and net-zero carbon emissions. It is suited to consumer and industrial applications such as power adapters, USB-PD chargers, and power supplies for home appliances, air conditioners, LED-lighting equipment, and smart meters.
The GaN converter operates in multiple modes to maximize efficiency at all line and load conditions. At heavy load, quasi-resonant (QR) operation with zero-voltage switching minimizes turn-on losses and electromagnetic emissions (EMI). At reduced load, valley skipping limits switching losses and leverages ST’s proprietary valley lock to prevent audible noise. Frequency foldback with zero-voltage switching ensures the highest possible efficiency at light load, with adaptive burst mode operation to minimize losses at very low load. In addition, advanced power management cuts standby power to below 30 mW.
Built-in features ensure safety and reliability, including output over-voltage protection, brown-in and brown-out protection, and input over-voltage protection. Input-voltage feedforward compensation is also provided, to minimize output peak-power variation, as well as embedded thermal shutdown, and frequency jittering to minimize EMI.