Driver circuit lights architectural and interior LEDs

摘要

LEDs are more efficient than incandescent lights and can last 100 times longer, but they require specialized electronic-drive circuits to avoid overstress conditions. The main operating parameter is relatively simple: Keep the current through the LEDs constant and under the specified maximum.Traditional power supplies have accurate voltage outputs with variations in current. A resistor in series with an LED string controls the current. Such a design assumes a known voltage across the LEDs that does not vary with changes in LED temperature. Unfortunately, LEDs' forward voltage does change with temperature. LED manufacturers generally bin their devices by forward voltage, allowing a lighting manufacturer to build a lighting fixture to match this forward voltage at a fixed temperature. A circuit using unbinned LEDs