Simple and efficient LED constant current drive circuit diagram

Based on the light-emitting characteristics of LED , this article proposes a wide voltage input, high efficiency, and high dimming ratio LED constant current drive circuit. This circuit has the advantages of simple structure, fast dynamic response, and no need for compensation circuits. Through external pins, LED switching, analog dimming and PWM dimming can be easily performed. The LED constant current drive circuit is based on CSMC's 1μm 40VCDMOS process and uses HSPICE for simulation verification. The results show that within the input voltage range of 8~30V, the maximum output current of the circuit can reach 1.2A, the output current accuracy can be controlled within 5.5%, and the power efficiency can be As high as 97%. The details are shown in the figure below: