A current intensity convertible CLD chip was fabricated using small and large FET cell configuration. Pinch off current of 8.82mA and 11.56mA were obtained for small and large cell in the CED chip, respectively. Constant current was fairly maintained until the breakdown voltage of 60 V, Measured knee voltage, Vk were 3.8 V and 4.5 V for small and large cell, respectively. We configured current amplifying chip with parallel connection of each cells, by connecting 8 individual large cells in parallel network, 92.0mA of current was obtained. The pinch off constant current of CLD chip was varied very linearly with respect to the number of parallel connected cell.

In this paper, by designing 20 W class driving circuit for driving high-power LED (Light Emitting Diode), we are going to comparatively carry out the analysis of characteristics for power circuit according to each design method. In this case, 200 V 60 Hz was performed as input data. The electrical characteristics such as voltage, current and ripple are checked for constant current circuit and constant voltage circuit in the LED module. In addition, as the ripple has an influence on illumination of LED light, low temperature working (-20 [℃]) and high temperature working(80 [℃]) are measured to make sure the ripple characteristics in accordance with temperature. In low temperature operation -20 [℃] measurements, both constant current circuit and constant-voltage circuit were less impacted on input fluctuation, whereas in the high temperature operation 80 [℃], current voltage in constant voltage circuit was surge after 430 [hour]. Voltage current ripple of constant current circuit was much less than constant voltage circuit, therefore we can show that constant current circuit is more stable.

In this paper, we have compared amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) with the nano-crystalline embedded-IGZO (Nc-embedded-IGZO) TFT fabricated by solid-phase crystallization (SPC) technique. The field effect mobility (μFE) of Nc-embedded-IGZO TFT was 2.37 cm2/Vs and the subthreshold slope (S-factor) was 0.83 V/decade, which showed lower performance than those of a-IGZO TFT (μFE of a-IGZO was 9.67 cm2/Vs and S-factor was 0.19 V/decade). This results originated from generation of oxygen vacancies in oxide semiconductor and interface between gate insulator and semiconductor due to high temperature annealing process. However, the threshold voltage shift (△V(TH)) of Nc-embedded-IGZO TFT was 0.5 V, which showed 1 V less shift than that of a-IGZO TFT under constant current stress during 10(5) s. This was because there were additionally less increase of interface trap charges in Nc-embedded-IGZO TFT than a-IGZO TFT.