SWITCHING MODE POWER SUPPLY HAVING DEVICES FOR REDUCING ELECTROMAGNETIC INTERFERENCE

摘要

An SMPS(Switching Mode Power Supply) is provided to minimize EMI(Electromagnetic Interference) and a noise by directly connecting a ferrite bead filter to a drain terminal of a transistor of a PFC(Power Factor Correction) and a converter. An AC power source is inputted to an AC input part(100). A filter part(200) removes a noise of an input power source. A rectifying part(300) rectifies the AC power source into a DC power source. A PFC(400) boosts an AC input voltage till DC 400V, and improves a power factor. A converter(500) converts the DC 400V boosted by the PFC. A first EMI improvement unit is directly connected to a drain terminal of a switching transistor of the PFC. The first EMI improvement unit reduces EMI and the noise of an output signal of the switching transistor of the PFC.