A novel low-cost current-sharing method for automotive LED-lighting systems

A novel low cost and passive current-sharing method for parallel connected LEDs is presented. The current-balancing concept is based on discontinuous inductor currents. An analysis has been performed and a prototype converter has been built and tested. The prototype converter drives 36 high-brightness LEDs consisting of six parallel strings with six high-brightness LEDs connected in series. The converter is designed for an automotive head-light system operating directly from the 14 V electrical automotive power net. Experimental results are in good correlation with theoretical predictions and demonstrate the good current-balancing performance.