150-W LED-driver design with 93 percent efficiency, 30 percent reduction in component count

June 07, 2012 // By Paul Buckley
Power Integrations has introduced a reference design kit for a 150 W, 48 V power supply for LED streetlights and other industrial/infrastructure lighting systems.

The driver circuit described in RDR-292 is more than 93% efficient at 230 VAC input and above 91% at 110 VAC. The design delivers a system power factor of greater than 0.97, THD of less than 10%, and easily meets EN61000-3-2 C. Designs can be scaled from 75 W to 400 W, using the same platform, simply by choosing different HiperPFS (PFC) and HiperLCS (LLC) family members and sizing power components appropriately.

RDK-292 requires fewer than 125 components to implement the driver’s PFC, LLC and standby power supply circuits, resulting in low BOM cost and exceptional reliability. The design utilizes a combination of Power Integrations’ highly integrated HiperPFS power-factor-correction IC and the HiperLCS resonant converter IC, which together save up to 35 components compared with conventional LLC solutions. HiperLCS also permits the use of smaller magnetics and output filter capacitors than typical LLC designs. The design incorporates a Qspeed merged PIN-Schottky diode as well, boosting CCM PFC efficiency by delivering greatly reduced diode recovery losses when compared with conventional ultrafast silicon PFC diodes.

For installations with remote lighting-control systems, the design implements highly efficient standby power-supply functionality based on Power Integrations’ LinkSwitch-TN ICs. The addition of a CAPZero X-capacitor discharge IC delivers further power savings, reducing no-load consumption to around 800 mW at 264 VAC input.

More information about the RDK-292 LED-driver at