A single soft switched resonant LED driver circuit

This paper presents a single switch soft switched buck-boost resonant converter for LED drive applications. Zero current switching condition results in high efficiency. The proposed circuit provides a constant average output current independent of output voltage which makes it suitable for LED drive applications. The average output current is independent of output voltage and is a function of switching frequency, resonance capacitor and input voltage. Thus in a specific output current the circuit works with a constant frequency and duty cycle, which makes the control circuit very simple. The circuit is suitable for cost sensitive applications due to minimized number of components. Boosting capability makes this converter proper to be connected to photovoltaic cells as the input power source. Simulation results for a 12V/60V converter are presented.