An analog implementation to improve load transient response of PFC pre-regulators

Martin K H Cheung, Martin H L Chow, Chi Kong Tse

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

5 Citations (Scopus)


This paper presents an analog implementation to improve the load transient response of PFC pre-regulators. By means of a notch filter inserted between the output-voltage sensing network of the pre-regulator and the voltage control loop of the pre-regulator control circuitry, the bandwidth of the voltage control loop is greatly expanded without introducing extra input current harmonics into the pre-regulators. This approach uses operational amplifiers with R-C networks to realize the notch filter, therefore it can be implemented into the existing pre-regulators with minor modification. The notch filter can be applied in both continuous-conduction-mode (CCM) pre-regulators and discontinuous-conduction- mode (DCM) preregulators. Furthermore the size of the output capacitor of the pre-regulators can be reduced due to the expanded bandwidth of the voltage control loop. The improved load transient response of the analog notch filter is observed experimentally. A laboratory prototype of a 100W DCM flyback pre-regulator has been built to illustrate the benefits of this cost-effective solution.
Original languageEnglish
Title of host publicationInternational Telecommunication Energy Conference, INTELEC 2007
Number of pages8
Publication statusPublished - 1 Dec 2007
EventInternational Telecommunication Energy Conference, INTELEC 2007 - Rome, Italy
Duration: 30 Sep 20074 Oct 2007


ConferenceInternational Telecommunication Energy Conference, INTELEC 2007

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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