A Hybrid-Input Negative Ring-type Converter Using Clean Energy Power Supplies

Abstract

For back-lighting applications, a white LED (WLED) driver using a hybrid-input negative ring-type converter is proposed in this paper. To drive the LED's cathode, the proposed driver offers the negative steppedup/stepped-down voltages by converting clean energy. The proposed driver can realize longer battery lifetime than conventional converters, because 1. In spite of the variation in clean energy input, the proposed step-up/step-down driver can utilize the clean energy effectively and 2. The proposed driver can charge a rechargeable battery when the back-light is standby mode. The properties of the proposed driver were clarified by theoretical analyses and SPICE simulations. SPICE simulations showed that the proposed driver can provide the sufficient voltage to drive LEDs by using not only battery energy but also clean energy. Furthermore, the theoretical formulas are useful for designing the proposed driver, because the theoretical results corresponded well with the simulation results.