Design and Development of Compact LED Driver For Long Life with PWM Dimming Functionality

Abstract

Solid state lighting like Light Emitting Diode (LED) lamps are eco-friendly, mercury-free, more energy efficient, able to ignite instantly and have longer lifetime, superior efficacy performance. Commercial / residential LED lamps should achieve high power factor greater than 0.9 according to Energy Star Criteria for Solid State Lighting Luminaries and harmonics of the input current should meet the IEC 61000-3-2 Class C standard. Large output capacitance is required at the output of the LED driver circuit to balance the energy difference between the input pulsating AC power and output DC power delivered to the LED load and minimize the low frequency LED output current ripple. There is a mismatch between the lifetime of electrolytic capacitors (5000 hours) and the LED (1,00,000 hours) that affects lifetime of overall LED system. A compact single-switch AC/DC high power factor electrolytic capacitor-less LED driver with integrated PFC circuit and step-down voltage conversion circuit is proposed here. Simulation and hardware models were developed on a 12-W LED lamp. A remote controlling technique is used to provide different dimming level function for even the non-dimmable LED lamps. The LED driver system also operates with high power factor of 0.95 in accordance with Energy Star Criteria for Solid State Lighting Luminaries and low Total Harmonic Distortion of 21% which is within the limits of IEC 61000-3-2 Class C standards.