Analysis and Design of Single-Switch Forward-Flyback Two-Channel LED Driver with Resonant-Blocking Capacitor

Analysis and Design of Single-Switch Forward-Flyback Two-Channel LED Driver with Resonant-Blocking Capacitor

Abstract:

In order to balance the light emitting diode (LED) current in each channel, many active and passive methods have been investigated. Among the various methods, the passive method using LLC converter with a blocking capacitor or flyback converter with a current sharing transformer (CST) in the secondary side is one of the simplest methods because it does not use any active component. However, LLC driver requires two main switches and external resonant inductor to obtain wide-output-voltage range. Also, flyback with a CST requires an additional magnetic component for CST and high-voltage rated diodes, resulting in the limitation of the cost and system volume. In this paper, a single-switch forward-flyback driver for two-channel LED is proposed. The most powerful advantage of the proposed driver is the cost-effectiveness, since it eliminates additional magnetic component. Furthermore, due to the reduced voltage stress on rectifier diodes compared to the flyback driver, the proposed driver achieves a higher efficiency. The prototype of 150-100V/0.3A two-channel LED verifies the effectiveness of the proposed work.

Comments are closed.