Fuzzy Logic Control With an Improved Algorithm for Integrated LED Drivers

This paper presents a fast fuzzy logic control algorithm for a Takagi-Sugeno-Kang fuzzy controller, which is applied to integrated LED drivers with the purpose of getting a good dynamic response and the reduction in the low-frequency (120 Hz) ripple. The algorithm uses the highspeed mathematical engine of a digital signal controller (DSC) that is capable to achieve fast multiplications during a common one-cycle instruction. Therefore, the execution time of the controller is improved with the use of a DSC. A scaling procedure is included in the program in order to use and to improve the accuracy of the multiplications and divisions in the DSC mathematical engine. A low-range DSC was used to program the proposed controller; therefore, the cost is affordable for LED driver applications. The fuzzy control curve was approximated to the sliding mode control (SMC) curve with the purpose of getting some of the good advantages of the SMC strategy like a good dynamic performance. The proposed controller is used to regulate the LED current. Simulation and experimental results are shown.