The compact, heatsink-free 46 W power supply delivers up to 95% efficiency, making it ideal for design engineers seeking lightweight, high-performance auxiliary power solutions.
Power Integrations has introduced a new reference design kit that is particularly valuable for design engineers working on energy-efficient, compact, and lightweight power supplies for solar-powered vehicles. Tailored for the upcoming Bridgestone World Solar Challenge, where student teams will race across the Australian Outback, this kit provides a practical solution for auxiliary power needs in solar race cars. Its focus on high efficiency, gallium-nitride switching technology, and design simplification makes it a strong reference point not only for student teams but also for engineers seeking to apply next-generation power electronics to mobility, renewable, and lightweight systems.
The reference kit, RDK-85SLR, is built around Power Integrations’ InnoSwitch3-AQ IC, which integrates the company’s proprietary PowiGaN gallium-nitride switch technology. This device is central to achieving efficiencies of up to 95 percent at both light and full load conditions, reducing energy losses and enhancing overall system performance. The design eliminates the need for a heatsink, thereby addressing key requirements for solar race cars—reduced weight, compact packaging, and improved reliability. For design engineers, this means fewer thermal management challenges, simplified integration, and lower system costs without sacrificing performance.
RDK-85SLR provides a complete blueprint for building a 46-watt auxiliary power supply, with the ability to deliver bursts of up to 80 watts for short durations. Such flexibility is well-suited for the demanding operational conditions of solar race vehicles, where auxiliary systems such as telemetry, lighting, or cooling must function efficiently without draining limited solar energy reserves. The kit includes a fully assembled power supply, four InnoSwitch3-AQ IC samples, an unpopulated PCB, and a comprehensive design report. This documentation covers transformer construction, schematics, PCB layout guidelines, a bill of materials, and performance data, enabling engineers to quickly adapt the design to their own applications.
The kit is not just a hardware package but also a teaching tool. It was inspired by a collaboration between Power Integrations’ PowerPros technical support team and ETH Zurich’s aCentauri solar racing team, whose challenger-class car ‘Silvretta’ successfully used the design in competition. Their experience demonstrated that PowiGaN-based systems could achieve exceptional performance while impressing scrutineering judges with an auxiliary power supply that required no heatsink. For student engineers and professionals alike, this reference design represents a concrete example of how gallium-nitride power semiconductors are reshaping design possibilities. By combining high efficiency, compactness, and robustness, the RDK-85SLR not only supports the solar race community but also illustrates how these technologies can transition into broader renewable energy and e-mobility markets.
Power Integrations has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
