ST extends VIPerGaN family with 65-Watt flyback converter in Power QFN
STMicroelectronics has added VIPerGaN65W, a 65 Watt flyback converter, in the VIPerGaN series that combines a 700V GaN transistor and quasi-resonant PWM control IC in a single QFN 5×6 package. Joining the VIPerGaN50W announced previously, the new VIPerGaN65W extends opportunities for customers to develop high-quality, cost-effective USB-PD chargers, fast battery chargers, and auxiliary power supplies.
The flyback controller of these converters operates in quasi-resonant mode with zero-voltage switching (ZVS) up to the full load. Valley skipping optimises efficiency at mid-to-high load, with ST’s proprietary valley locking to prevent noise at audio frequencies and thus ensure silent operation. With frequency foldback at light load, the converter enters burst operation at no-load to cut power consumption below 30mW for eco-design compliance.
The integrated gate driver is fine-tuned for the GaN transistor parameters, which saves designers adding external components to optimise switching, helping accelerate time to market, increase power density, and minimising the bill of materials. High-voltage startup circuitry, and a senseFET for accurate current monitoring, are also integrated.
Like the VIPerGaN50W, the new VIPerGaN65W includes advanced power-management features that improve performance compared to ordinary flyback circuits. There is line-voltage feedforward, which prevents the output power increasing excessively as the supply voltage changes, and dynamic blanking time that limits the operating frequency to minimise switching losses. Input and output overvoltage protection, thermal shutdown, and brown-in and brown-out protection are also built-in.
The EVLVIPGAN65WF evaluation board is available to help explore the VIPerGaN65W features and kick-start customers’ projects. The board implements a 24V/65W isolated flyback converter with secondary-side synchronous rectification, ready to operate with any AC input voltage from 90V to 265 V.
