Single-Phase Active LED Driver with common cathode DC-DC Buck Cell with Constant Output Current without Electrolytic Capacitor

An LED driver based on η
χ
power stage (PS) design is being discussed in this paper. Required MPP can be obtained by controlling the power flow using the control (power) switches that in turn leads to storage capacitance reduction which improves the driver life span. where η
χ
indicates the number of times the power is getting processed before it is fed to the output for the LED driver considered. With MPP design, DC-DC converter needs to process only a portion of input power and not entire power which is the case of two-stage LED driver. This will improve the overall system efficiency. Additionally, the double line frequency power which is unavoidable for any single-phage AC-DC configuration is attenuated. AC input ripple power can be balanced with dc output power by proper switching timings of power switches. Thus, electrolytic capacitor can be removed from the design which increases system life span. But obtaining required MPP, input PFC and COC increases the complexity in design, complexity in controlling and also increases the component count. A 38W simulation model is designed on PSIM and results are verified.