Design and Measurement of FA Leakage Current EM1 Filter

In this paper, a re-design of low power singlephase EM1 filler where less than 100 ,u4 of leakage current as per UL 2601-1 standards will be presented. The recent current limit is more stringent for medical applications than the others. Hence there is a need to revisit the EM1 filter design. The two Y capacitors are the major contributors to fhe leakage current due to the equivalent series resistor (ESR). ' The three-Y capacitors are suggested for the strategy. The experimental data indicates that low leakage current is achieved and the filter provides an average of 67 dB insertion loss in the 150 kHz to 30 MHz band. Mutual coupling is investigated bur it does not contribute to the leakage currenf at lowpower.