CMOS LED Driver Design Of Precision Current Source Circuit

The current source circuit of (LED) is used for providing the stable current for LEDlight-emitting diodes. The color and the brightness of the LED has connection with itselectricity flow. As for the good performance of the LED, some important indicators arestability, accuracy and the temperature of the current. This essay uses the tool ofCadence EDA and adopts the0.5μm standard CMOS processing condition to design adriving LED constant current source circuit. The circuit is mainly contains the bandgapreference voltage source, the buffer circuit, two stage operational amplifier, currentsource circuit modules. Working voltage of the constant current source circuit is5V.When the scope of the voltage is within20%, the environment temperature changesfrom45centigrade to80centigrade, the constant current source circuit of the outputcurrent is32mA.