LED-TV용(用) 전원장치에 적합한 Hybrid 초크 코일의 특성 해석에 관한 연구

Abstract

This paper presents the intra capacitance modeling according to the winding method, section bobbin and coil structure for hybrid choke coil capable of the EMI attenuation of broad bands from lower frequency bands to higher frequency bands and high frequency type common-mode choke coil capable of the EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. In case of high frequency type CM choke coil, it can be explained the parasitic capacitance of A type and section bobbin type winding methods among them is much smaller than the other. The first resonant frequency of the proposed CM choke coil tends to increase as the parasitic capacitance becomes small and its impedance characteristics also show improved performance as the first resonant frequency increases. In case of hybrid choke coil using rectangular copper wire, it has investigated its parasitic capacitance compared to CM choke coil of conventional toroidal type becomes small. Also it has confirmed through the experiment results that CE margin and RE margin in frequency bands 0.5MHz to 5MHz and 30MHz to 200MHz are respectively 10dB and 15dB greater than that of conventional type in case of one stage EMI filter structure adopting hybrid choke coil compared to two stage EMI Filter structure using two of each CM choke coil used in the lower and higher frequency bands or two of CM choke coil used in only the lower frequency bands. In the future, the hybrid choke coil and CM choke coil of high frequency type show it can be practically used in not only LED/LCD-TV SMPS but also several applications such as LED Lighting, Laptop Adapter, Server Power Supply and so on.