LED Drive IC Technology Using Constant Current Drive Method

Recently, LEDs have shown explosive growth in application areas ranging from LCD backlighting, camera phone flashes, automotive light sources, traffic signals, therapeutic light sources, and general lighting. This is attributable to the advantages of LEDs such as improved luminous efficiency, long lifespan, low maintenance costs, and environmental friendliness. This expansion of LED applications is accompanied by increased demand for LED drivers for their proper operation. An LED is a current-driven device whose brightness is directly proportional to forward current. There are two major reasons why LEDs must be driven with constant current: ensuring reliability by not exceeding the maximum rated current of the device, and obtaining desired optical characteristics precisely. Through this seminar, we introduce LED driver circuit technology, discuss constant-current driving LED Driver IC technology being developed by the Electronics and Telecommunications Research Institute, examine currently common LED driving methods and their problems, and review proper LED driving methods.