Design of a Constant LED Driver Circuit with Temperature Compensation

This paper presents the implementation of a constant current LED driver with temperature compensation The temperature compensation circuit is in order to maintain LEDs' stable and reliable operation. There is a thermistance mounted close to LEDs, which is a negative temperature coefficient resistor. When the ambient temperature near LEDs goes high and the negative temperature coefficient thermistor samples the temperature of the LED's and give feedback to the temperature compensation module. In the paper, the LED driver also considers over temperature protection. When the LED driver chip temperature rises to a certain amount, it forces to shutdown. The sampling the temperature of the LED's reaches the value of threshold resistance, LEDs' current starts to reduce automatically. If the ambient temperature is too high, it forces the driver to shut down. The Spectre simulation and Matlab simulation results are shown, which are in correspondence to theoretical anticipation.