Power Integrations' DER-340
long-lifetime non-isolated buck LED driver reference design describes a wide range (90 VAC to 308 VAC), high power factor (>0.95) LED driver power supply that is suitable for high-bay, exterior and street-lighting applications. The 40.5 W driver detailed in the new reference design uses the company's LinkSwitch-PH family of power conversion ICs which combine single-stage PFC and CC output control. High-voltage aluminum electrolytic bulk capacitors are not required in the single-stage approach, making 50,000-hour lifetimes attainable. In addition to effectively driving standard lighting applications in benign environments, the driver copes with conditions of poor ventilation and high temperatures in industrial applications. The single-stage topology also reduces component count, allowing use of single-sided boards and smaller enclosures. Energy-efficiency is high, operating above 88% at 230 VAC and over 87% at 120 VAC, while output current tolerance is less than 5% across line, load and temperature. The DER-340 LED driver reference design is available for free download at the company's website.