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Design of PFM Boost Converter with Dual Pulse Width Control

이중 펄스 폭을 적용한 PFM 부스트 변환기 설계

  • Choi, Ji-San (Inha University Department of Electronic Engineering) ;
  • Jo, Yong-Min (Inha University Department of Electronic Engineering) ;
  • Lee, Tae-Heon (Inha University Department of Electronic Engineering) ;
  • Yoon, Kwang-Sub (Inha University Department of Electronic Engineering)
  • Received : 2015.06.08
  • Accepted : 2015.09.04
  • Published : 2015.09.30

Abstract

This paper proposed a PFM(pulse-frequency modulator) boost converter which has dual pulse-width. The PFM boost converter is composed of BGR(band gap voltage reference generating circuit), voltage reference generating circuit, soft-start circuit, error amplifier, high-speed comparator, inductor current sensing circuit and pulse-width generator. Converter has different inductor peak current so it has wider load current range and smaller output voltage ripple. Proposed PFM boost converter generates 18V output voltage with input voltage of 3.7V and it has load current range of 0.1~300mA. Simulation results show 0.43% output voltage ripple at ligh load mode and 0.79% output voltage ripple at heavy load mode. Converter has efficiency 85% at light lode mode and it has maximum 86.4% at 20mA load current.

본 논문은 이중 펄스 폭을 지닌 PFM(Pulse-Frequency Modulator) 부스트 변환기를 제안한다. 부스트 변환기의 구동 회로 구조는 밴드 갭 기준 전압 발생 회로와 이를 이용해 여러 가지의 기준 전압을 생성하는 기준 전압 발생 회로, 소프트 시동 회로, 에러 증폭기, 고속 전압 비교기, 인덕터 전류 센싱 회로, 펄스 폭 발생 회로로 구성되어있다. 변환기는 부하 전류 상태에 따라 서로 다른 최대 인덕터 전류 값을 갖도록 구성해 부하 범위를 넓히고, 출력 전압 리플을 감소하도록 했다. 제안된 PFM 부스트 변환기는 입력 전압으로 3.7V를 받고, 18V의 출력 전압을 생성한다. 구동 가능한 부하 전류는 0.1~300mA의 범위를 가진다. 모의실험 결과 저 부하 전류 동작 구간에서 0.43%, 고 부하 전류 동작 구간에서는 0.79%의 출력 전압 리플을 보였다. 변환기는 저 부하 구간에서 85%의 효율을 나타내며 20mA에서 86.4%로 최대의 효율을 나타냈다.

Keywords

References

  1. E. Sanchez-Sinencio and A. G. Andreou, "Low-voltage/ low-power integrated circuits and systems," IEEE PRESS, 1998.
  2. U. Sengupta, "PWM and PFM operation of DC/DC converters for portable applications," TI Power Supply Design Seminar, vol. 1700, 2007.
  3. X. Liu, S. Guo, S. Wang, F. Xu, G. Du, and Y. Chang, "Analysis and design of a high efficiency boost DC-DC converter based on pulse-frequency modulation," Int. Symp. Integrated Circuits, pp. 398-401, Singapore, 2007.
  4. M. Al-Shyoukh and H. Lee, "A compact fully-integrated extremum-selector-based softstart circuit for voltage regulators in bulk CMOS technologies," IEEE Trans. Circuits Syst. II: Express Briefs, vol. 57, no. 10, pp. 818-822, 2010. https://doi.org/10.1109/TCSII.2010.2058597
  5. K. Lee, "Design of high dimming ratio power-LED driver with preloading inductor current method," M.S. Thesis, Inha Univerity Graduate school, pp. 45-46, 2013.
  6. Y.-S. Kim, B.-M. No, J.-S. Min, S. Al-Sarawi, and D. Abbott, "On-chip current sensing circuit for current-limited minimum off-time PFM boost converter," SoC Design Conf. (ISOCC), pp. 544-547, Busan, Korea, Nov. 2009.
  7. R. C.-H. Chang, H.-M. Chen, C.-H. Chia, and P.-S. Lei, "An exact current-mode PFM boost converter with dynamic stored energy technique," IEEE Trans. Power Electron., vol. 24, no. 4, pp. 1129-1134, Feb. 2009. https://doi.org/10.1109/TPEL.2008.2011486
  8. H.-H. Wu, C.-L. Wei, Y.-C. Hsu, and R. B. Darling, "Adaptive peak inductor current controlled PFM boost converter with a near-threshold startup voltage and high efficiency" IEEE Trans. Power Electron., vol. 30, no. 4, pp. 1956-1965, May 2014. https://doi.org/10.1109/TPEL.2014.2323895