Cost-effective single switch multi-channel LED driver

In this paper, we propose a cost-effective single switch multi-channel LED (light emitting diode) driver. While conventional LED drivers require as many non-isolated DC/DC converters as the number of LED channels, the proposed LED driver needs only one power switch and several balancing capacitors instead of expensive non-isolated DC/DC converters. Therefore, the proposed driver features a simpler structure, with lower cost, and higher efficiency. In particular, because its power switch can be turned off under the zero current switching condition, it has very desirable advantages such as improved electromagnetic interference characteristics and high efficiency. Moreover, it uses only a small number of DC blocking capacitors with no additional active devices for current balancing of multi-channel LEDs, so the proposed driver exhibits high reliability and is cost effective. To confirm the validity of the proposed driver, we perform a theoretical analysis, and present design considerations and experimental results obtained from a prototype that is applicable to a 46” LED-TV.