발광다이오드용 정전류 회로 설계에 관한 연구

A Study on the Supplying Constant Current Circuit Design for Light Emitting Diode

In this paper, We are study on the constant current circuit for Control of LED which are high-efficiency light-emitting diode. Designed circuit which are with out Constant voltage or constant current circuit IC provide a stable constant current effectively with the number of small devices and It was a stable output in spite of the LED device characteristics change according to the process variables. In addition, around or change the temperature of the product itself is to provide a stable constant current. Therefore, we are design the PWM constant current circuit using multiple devices and Capacitors for the pulse-width modulation. If the load has a High-voltages(12V, Vdd) and 0.2W multi-chip LED 4 bulbs, the power consumption of the conventional circuit for LED is approximately 1440mW and efficiency was 55.5%. On the other hand, The power consumption of the proposed constant current circuit for LED was approximately 960mW and efficiency was 83.3%. It‘s mean the power consumption of the proposed constant current circuit is higher than the conventional one for LED and Energy savings rate was 33.3% above of them.