EVL6563S-250W演示板

GY@艳

EVL6563S-250W演示板实现了一个功率因数校正（PFC ）预调节器， 250 W连续功率，从大范围的电源电压提供一个稳定的400 V电压轨和提供的电源高次谐波的减少，从而使欧洲EN61000-3- 2或日本JEITA - MITI标准得到满足。稳定的输出电压，通常是输入的级联隔离DC-DC转换器，它提供了所要求的输出轨负载。This demonstration board implements a power factor correction (PFC) pre-regulator, 250 W continuous power, delivering a regulated 400 V rail from a wide range mains voltage and providing for the reduction of the mains harmonics, allowing the European EN61000-3-2 or the Japanese JEITA-MITI standard to be met. The regulated output voltage is typically the input for the cascaded isolated DC-DC converter which provides the output rails required by the load.The power stage of the PFC is a conventional boost converter, connected to the output of the D1 rectifier bridge. It is completed by the L2 coil, the D3 diode and the C5 capacitor. The boost switch is represented by the Q1 and Q2 power MOSFETs, connected in parallel. The NTC R1 limits the inrush current at switch-on. It has been connected on the DC rail, in series to the output electrolytic capacitor, in order to improve the efficiency during low-line operation. In fact the RMS current flowing into the output stage is lower than current flowing into the input stage at the same input voltage. The board is equipped with an input EMI filter necessary to filter the switching noise coming from the boost stage.