High-Efficiency AC/DC ZVS Flyback Architecture With Leading Non-PFC Output Power
70 W high-power-density solution with over 94.5% efficiency removes the need for power factor correction in higher-power designs, offering enhanced performance with a reduced bill of materials.
Eggtronic has introduced a 70 W version to its ‘QuarEgg’ ZVS Flyback family, offering high-density power conversion solutions with ultra-high efficiency. This allows designers to increase power output without implementing power factor correction (PFC), as required by European standard EN61000-3-2 for power supplies rated above 75 W. The market has favoured 65 W AC/DC converters to avoid exceeding the 75 W threshold. However, it enables engineers to develop non-PFC designs supporting up to 70 W, expanding the range of applications that can benefit from this technology.
The key features include:
- 5 x 5 mm device enhances performance at zero and light loads
- Protects against overvoltage, overcurrent, brownout, and extreme temperatures
- Demonstrated in a compact form factor of 72.6 mm x 39.1 mm x 17.5 mm
- Delivers 70 W output power
The new model is built on the company’s patented low-loss, forced zero voltage switching (ZVS) flyback architecture, achieving efficiencies over 94.5% across the entire load range, even in challenging scenarios such as a low 90 V input voltage with a full load. This architecture allows designers to significantly reduce operational losses compared to conventional active clamp flyback (ACF) and quasi-resonant (QR) topologies, simplifying circuit design and thermal management and reducing component count, size, and cost.
At its core lies the company’s EPIC QuarEgg IC, a mixed-signal, low-power controller with multi-mode operation and synchronous rectification control.This architecture is suitable for chargers for portable equipment, set-top boxes, routers, Bluetooth speakers, IoT devices, small consumer devices, and high-brightness LED lamps.
Eggtronic’s CEO and founder, Igor Spinella, highlights that integrating PFC into designs increases complexity, component count, and size, which are aspects OEMs aim to minimise. With the new 70 W QuarEgg, designers can now create PFC-free designs with higher power than previously possible, offering smaller form factors and costs comparable to QR alternatives.