Power Integrations has extended the power range of its flyback topology to 440W, creating a power supply solution that is simpler than resonant designs

The new TOPSwitchGaN ICs more than double output power whilst reducing system costs, simplifying system architecture and shortening design cycles

Power Integrations (Nasdaq: POWI) today unveiled a breakthrough in flyback topology, extending the power range of flyback converters to 440W—far beyond the limits traditionally achievable with more complex LLC resonant topologies. The new TOPSwitchGaN flyback IC family combines the company’s breakthrough PowiGaN technology with its iconic TOPSwitch IC architecture, simplifying system design, eliminating the need for heat sinks in many cases, shortening design cycles, improving manufacturability and reducing overall system costs.

Silvestro Fimiani, Director of Product Marketing at Power Integrations, said, “This is not merely a product upgrade—it represents a fundamental shift in the way engineers approach power supply design. For decades, as power levels increased, designers have had to turn to resonant topologies such as LLC. With TOPSwitchGaN, we have extended the flyback topology into previously unattainable power ranges, enabling engineers to achieve high efficiency and performance through a far simpler architecture.”

Integrated solutions utilising TOPSwitchGaN achieve 92% efficiency across a load range of 10% to 100%, with power consumption in standby and off-mode below 50mW, easily meeting the requirements of the European Energy-related Products (ErP) regulations. The device achieves this performance without the need for synchronous rectification, making it an ideal choice for high-end household appliances, e-bike chargers and industrial applications.

The RDS(ON) of PowiGaN switches is significantly lower than that of silicon switches, resulting in reduced conduction losses and a significant increase in the power handling capability of flyback converters. These new devices utilise 800V-rated PowiGaN switches, offering excellent surge immunity and low switching losses, and can operate at switching frequencies of up to 150kHz, minimising transformer size.

At a 230V AC input voltage (with input voltage detection enabled), no-load power consumption is well below 50mW; when the device is in standby mode, it can still deliver up to 210mW of output power whilst drawing 300mW of input power at 230V AC, serving as a standby auxiliary power supply for the device.

Fimiani continued, “TOPSwitch is the first device to integrate an off-line power switch into a small package, with billions sold since 1994; the name represents innovation in the field of power conversion. Engineers rely on TOPSwitch for its high efficiency and ease of use, and now these advantages will benefit a wider range of design applications. TOPSwitch GaN extends the power range of flyback architectures to an unprecedented 440W, allowing flyback circuits to be applied in areas that previously required more complex topologies.”

The new IC is available in two package options. For ultra-thin designs, the flat eSOP-12 surface-mount package delivers 135W (85–265VAC) output power without the need for a heat sink, making it suitable for applications such as household appliances. The vertical architecture of the eSIP-7 package minimises PCB footprint, whilst offering thermal resistance comparable to that of TO-220 packaged devices. By using a metal heat sink mounted via simple clips, a wider power range can be achieved, making it suitable for applications such as power tools, electric bicycles and garage door access control systems. As the TOPSwitchGaN IC is pin-compatible with the TinySwitch-5 off-line switching power supply IC, designers can employ the same solution for applications ranging from 10W to 440W.

Availability and Resources

TOPSwitchGaN is priced from US$1.00 (minimum order of 10,000 units). The following reference design materials are available:

• DER-1079  – This solution utilises the TOP7074K to provide a 60W isolated flyback power supply with a wide input voltage range for household appliances;
• DER-1019 – This solution is a 356W high-voltage (89V / 4A) isolated flyback industrial power supply utilising the TOP7078E;
• RDK-1018 – This electric bicycle charger solution features a 168W wide-range isolated flyback design based on the TOP7075E.