A boost Power Factor Correction (PFC) circuit is connected between the AC grid and converters to meet Electromagnetic Interference (EMI) standards. The EMI filter should be attached at the input of the boost PFC to attenuate high-frequency noise injected into the grid. This article discusses the boost PFC with sliding frequency modulation proposed by Power Integrations. The proposed boost PFC is compared to a conventional boost PFC operated at 120 kHz. Both boost PFC circuits have a nominal power of 300 W, and a DC voltage of 390 VDC. The EMI filter design procedure with practical guidelines is presented.
