50W GaN Converter Enables High-Efficiency Power Designs


The STMicroelectronics VIPerGaN50 simplifies building single-switch flyback converters up to 50 Watts and integrates a 650V gallium-nitride (GaN) power transistor for superior energy efficiency and miniaturization.

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 5mm x 6mm 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 ecodesign 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 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 30mW.

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.

The VIPerGaN50 is in production now and available in a 5mm x 6mm QFN package, from $2.30 for orders of 1000 pieces. The device is in a free-sample program and can be ordered on ST eSTore.