LED driver reference design targets 100W incandescent bulb replacements

September 03, 2012 // By Christoph Hammerschmidt
Power Integrations, maker of efficient, long-lasting off-line LED driver ICs, announced DER-323, a reference design for an 18W, 88%-efficient, non-isolated A19 LED driver based on LNK460VG, a low-profile IC from the company’s LinkSwitch-PL family. The design is suitable for a 100 W incandescent bulb replacement and is optimized for low-line (90 VAC to 135 VAC) operation. The circuit is low-cost, requiring only a simple single-sided board and 25 components. No potting is necessary and the transformer is replaced by a low-cost inductor.

DER-323 utilizes a simple buck-boost converter topology that fits easily inside the A19 bulb. The design is EN61000-3-2 (C) compliant and has a high power factor of over 0.98, easily satisfying commercial and consumer compliance requirements. Because LinkSwitch-PL ICs combine both PFC and CC converter functions in a single-stage topology, no electrolytic bulk capacitor is required, resulting in a very long operational life.

According to product marketing manager Andrew Smith, the lighting industry typically asks for 80% efficiency for drivers targeting 60 W A19 bulb replacements. To achieve viable LED-based replacements for 75 W and 100 W bulbs, much higher efficiency is needed in order to reduce the heat dissipated by the driver. The 88% efficiency of DER-323 satisfies this need and makes the thermal design of the bulb straightforward and inexpensive. Features such aslow component count, single-stage architecture and use of a low-cost inductor rather than a transformer help to keep the price level for the product low.

DER-323 is available for download at: