Cascaded hybrid analog modulated linear LED driver for DC distribution system

Abstract

DC grids are becoming popular due to higher efficiency and simple solar integration architecture. DC grids enable implementation of simple structures like compact linear LED drivers. But due to variations in LED characteristics from one batch to another batch (variation in manufacturing process) and use of dimming to control light output, implementation of compact linear LED drivers results in loss of efficiency. To overcome the problem of variations in LED voltage, cumbersome binning process may be employed. But with aging or/and temperature variation, this implementation does not result in satisfactory solution. In the proposed model, low cost small compact boost converter is serially connected with analog modulated/unmodulated linear LED driver. In the proposed driver, mini-boost driver of one-tenth capacity is employed in series with linear driver for providing variable constant current to facilitate wide dimming range.