The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Design of the DC-DC Buck Converter for Mobile Application Using PWM/PFM Mode

PWM/PFM 모드를 이용한 모바일용 벅 변환기 설계

  • 박리민 (인하대학교 전자공학과 아날로그집적회로설계 연구실) ;
  • 정학진 (인하대학교 전자공학과 아날로그집적회로설계 연구실) ;
  • 유태경 (인하대학교 전자공학과 아날로그집적회로설계 연구실) ;
  • 윤광섭 (인하대학교 전자공학과)
  • Received : 2010.03.05
  • Accepted : 2010.10.18
  • Published : 2010.11.30
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Abstract

This paper presents a high efficiency DC-DC buck converter for mobile device. The circuit employes simplified compensation circuit for its portability and for high efficiency at stand-by mode. This device operates at PFM mode when it enters stand-by mode(light load). In order to place the compensation circuit on chip, the capacitor multiplier method is employed, such that it can minimize the compensation block size of the error amplifier down to 30%. The measurement results show that the buck converter provides a peak efficiency of 93% on PWM mode, and 92.3% on PFM mode. The converter has been fabricated with a $0.35{\mu}m$ CMOS technology. The input voltage of the buck converter ranges from 2.5V to 3.3V and it generates the output of 3.3V.

본 논문에서는 무선 휴대 장치의 전력공급을 위해 적용 가능한 고효율 PWM/PFM 모드 DC-DC벅 변환기를 제안한다. 휴대성 확보를 위한 간소화된 보상회로를 사용하고, 휴대장치의 대기 모드 및 저부하에서 높은 효율을 갖도록 설계하였다. 휴대 장치 동작 시간의 대부분을 차지하는 대기모드(저부하: 60mA이하) 및 저부하에서의 고효율 동작을 해서 PFM 동작 모드의 제어를 위해서 상대머신을 설계하였다. 칩 측정 결과 동작모드별로 PWM은 93%, PFM은 92.3%의 최대효율을 확인하였다. 측정된 출력 리플전압은 10mV 이하로 나타났다. 제안된 벅 변환기는 $0.35{\mu}m$ CMOS 공정으로 제작하였으며, 3.3V ~ 2.5V의 입력전압을 받아서 1.8V의 전압을 출력하였다.

Keywords

References

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