Efficiency comparison between Si and SiC-based implementations in a high gain DC-DC boost converter

An efficiency comparison between a boost converter implemented with silicon (Si) devices and the same converter implemented in the other three cases, that is, employing two combinations of silicon carbide (SiC) devices and a mixture of Si and SiC elements is presented. The converter has been designed for high-voltage low-power applications required by light-emitting diode (LED) lighting. The comparison is performed on an equal basis and discusses the influence on the converter efficiency of the semiconductor power devices and the passive components. The experiments are carried out in a single-stage boost converter prototype delivering a maximum output voltage of 1200 V when supplied by a 12 V battery. The measurements show that the highest efficiency is obtained when the power transistor is implemented by a normally-off junction field-effect transistor and the diode by a SiC Schottky device with a small parasitic capacitance. The implementation with the highest efficiency has been selected for supplying a light spot of 320 LEDs in series, which results in an output voltage of 956 V and an output power of 20.6 W.