Si ve GaN Yarı İletken tabanlı SEPIC DC-DC Led Sürücülerin Karşılaştırılması

Abstract

Recently, in power electronics, studies on creating new semiconductor concept is so popular. As a result of this studies, using of wide band gap semiconductors (WBG) such as Silicon Carbide (SiC) Mosfets and Gallium Nitride High Electron Mobility Transistors (GaN-HEMT) has gained much attention due to the its high switching frequncy capability and providing high power density feature. Furthermore, in the field of illumination, power leds is so eye cathing because of their high efficinecy feature with respect to other kind of illumination such as metal halide and incandesant bulbs. In addition, to operate power leds, DC power is required and the most efficient way to provide required DC power is to use one of the DC-DC converter topologies. Buck-boost derived converter topology is the best solution fort that purpose. One of the flashiest topologies is single ended primary inductor (SEPIC) converter. Therefore, in this paper, comparison of SEPIC DC-DC converter-based power led driver using silicon (Si) and enhancement mode (E-mode) GaN-HEMT based power switch is made. Also, SEPIC led drivers are designed for 10W power led and implementations for both power switches are realized. In addition, switching frequency of converters is chosen as 100kHz and dsPIC30F4011 micro controller is used to produce PWM signal for power switches and to limit maximum current of power leds by using ACS712 current sensor. By means of the applications, power led current, power led voltage, input current, input voltage and input side inductor current, switch voltage, gate resistor voltage are measured and compared for both Si and GaN based power switches. As a result of comparisons, altough similar results are obtained, circuit using Si MOSFET has slightly higher efficiency than E-Mode GaN-HEMT used circuit. Besides, circuit using E-Mode GaN-HEMT is more sensitivity to the noises and needs extra care for its soldering.