| Abstract |
Insulated DC-DC switching power supplies have been using a magnetic coupling method using atransformer for several decades. Transformers have excellent properties as a material that can changethe voltage while insulating. On the other hand, it can be considered that there is a limit to thereduction in size and weight with increasing switching frequency. Therefore, we are interested in theinsulation type converter by the capacitor coupling. The principle of the capacitor insulation methodwas introduced in 1994, but it was pointed out that the problem of noise that occurs when the powerdevice is turned on and off. After that, a case where noise was suppressed by using a series resonantcircuit of a capacitor and an inductor was reported. However, it had no means to control the outputvoltage, and had the problem that fluctuations in the input voltage would directly cause fluctuations inthe output. Therefore, we maintain "resonance state" by providing "two sets of LC resonance tankcircuits corresponding to the resonance frequency" and changing the operating frequency for ONwidth pulse of fixed width (pulse frequency modulation or pulse density modulation). We propose thatthe output voltage can be controlled while. The voltage control characteristics are analyzed usingSpice Simulation, and the Co-relation with the experimental value is confirmed. By usingfrequency/density modulation, the inverter is always switched at the current zero crossing point,enabling Noiseless switching. Regarding the possibility, we will analyze the switching characteristicsdue to the deviation from the resonance point by using ADS; Electronic Design Automation tool, forthe noise that may occur in the actual PCB (circuit pattern), and show the results. |
