Investigation of the Use of Switched Capacitor Converters as LED Drivers

This paper investigates the use of switched capacitor converters to implement DC-supplied LED drivers with PWM dimming functionality. A voltage doubler switched capacitor converter is selected as an example of LED driver implementation. The converter is analyzed, and the main characteristics and equivalent circuits are obtained. The current waveform of the switched capacitor is calculated considering the stray inductance of the converter. The implementation of PWM dimming in this type of LED driver is also investigated. A 44-W laboratory prototype operating at 100 kHz switching frequency and 25 kHz dimming frequency has been developed to verify the theoretical analysis and evaluate the operation of the LED driver.