Driver circuit simplifies LED lighting design

Power Integrations has devised a simple, ultra-low-component-count driver circuit for offline LED lighting.

Power Integrations has devised a simple, ultra-low-component-count driver circuit for offline LED lighting.

The circuit requires only nine components to deliver 40mA of current and 0.5W of output power - an ideal level for emergency exit signs, nightlights and a variety of other lighting applications.

The design, entitled DI-92, uses LNK302, a member of Power Integrations' LinkSwitch-TN family of integrated circuits.

DI-92 is a constant-current LED driver circuit using a nonisolated buck-boost topology.

The design's low component count makes it extremely small, lightweight and inexpensive, with a materials cost of approximately US $0.50 (in unit quantities of 10,000).

The circuit is also environmentally friendly, operating at up to 75% efficiency, well above the level achievable with passive designs.

"Solid-state lighting is gaining popularity in applications where long lifetimes and low maintenance are important, such as emergency exit signs, traffic lights and commercial signage", said Rich Fassler, Director of Product Marketing for Power Integrations.

"Another key benefit of LED lighting is energy efficiency, which makes our EcoSmartE power conversion technology a natural fit for this market".

"As the efficiency of solid-state technology increases over time, LEDs will find applications in the general lighting market, presenting an even greater opportunity for Power Integrations' energy-efficient power conversion ICs".

The DI-92 circuit design operates across the entire global range of AC input voltages, from 85 to 265V.

It meets EMI specifications CISPR22B/EN55022B with a margin of more than 8dB, and is Class II safety-compliant.

Back to top