High-Voltage Converters Bring the Power to Energy-Efficient Appliances
Integrating the power switch, gate driver, and flyback control, STMicroelectronics' latest VIPerGaN high-voltage Monolithic GaN converters significantly increase energy savings in domestic appliances, building and home automation, smart lighting, and consumer products.
The VIPerGaN100W has a 3.5-A drain current limit, while the VIPerGaN100WB has a 4.2-A current limit for handling short-term peak power up to 125 W. Both converters have an AC input voltage range from 85 to 265 V, and can deliver up to 100 W from a 185-V supply.
The 700-V GaN power transistor in each converter offers a low RDS(on) of 0.27 mΩ, which also aids thermal performance. The 5- × 6-mm QFN devices' integrated flyback converter and GaN gate driver save time when fine-tuning gate resistance and inductance to optimize switching performance.
The EVLVIPGAN100WP reference design for a 100-W USB Type-C Power Delivery 3.0 adapter features the VIPERGAN100W, with five output settings from 5V/3.0 to 20V/5.0 A, secondary-side regulation, and optocoupler feedback. The reference design has peak efficiency over 92% and a power density of 24 W/in.3.
ST’s proprietary valley lock stabilizes the number of valleys skipped to prevent variations at audio frequencies for silent operation at all loads. Burst-mode operation at no-load cuts power consumption to below 30 mW.
Line-voltage feedforward sharpens control of energy per cycle, stabilizing power as the input voltage fluctuates, and dynamic blanking time limits the change in switching frequency to minimize switching losses. Both converters have protection against input and output overvoltage, overtemperature, brown-in, and brown-out.
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About the Author
Alix Paultre
Editor-at-Large, Microwaves & RF
Alix is Editor-at-Large for Microwaves & RF.
An Army veteran, Alix Paultre was a signals intelligence soldier on the East/West German border in the early ‘80s, and eventually wound up helping launch and run a publication on consumer electronics for the U.S. military stationed in Europe. Alix first began in this industry in 1998 at Electronic Products magazine, and since then has worked for a variety of publications, most recently as Editor-in-Chief of Power Systems Design.
Alix currently lives in Wiesbaden, Germany.