DOI QR코드

DOI QR Code

외부 커패시터 없이 넓은 주파수 범위에서 높은 PSRR 갖는 LDO 설계

A Design of High PSRR LDO over Wide Frequency Range without External Capacitor

  • Kim, Jin-Woo (Department of Electronics Engineering, Seokyeong University) ;
  • Lim, Shin-Il (Department of Electronics Engineering, Seokyeong University)
  • 투고 : 2013.09.11
  • 심사 : 2013.11.22
  • 발행 : 2013.12.25

초록

본 논문은 외부 커패시터 없이 광범위 하게 높은 전원 공급 잡음 제거비(PSRR)을 갖는 선형 정류기(LDO)에 관한 것이다. 제안된 LDO는 높은 PSRR과 안정도를 유지하기 하기 위해 nested Miller 보상 기술을 사용하였고, 내부적으로 캐스코드(cascode) 보상과 전류버퍼(current buffer) 보상 기술을 사용하였다. 또한 외부의 부하 커패시터가 없기 때문에 외부 하드웨어 비용을 최소화 하였고, 제안된 보상 기법을 사용하여 내부에 작은 커패시터를 사용하고도 안정도를 확보할 수 있었다. 설계된 LDO는 2.5V~4.5V의 입력 전압을 받아서 1.8V의 전압을 출력하고 최대 10mA의 부하 전류를 구동할 수 있다. 일반 0.18um CMOS 공정을 이용하여 제작하였고 면적은 300um X 120um 이다. 측정된 PSRR은 DC일 때 -76dB, 1MHz일 때 -43dB를 만족한다. 동작 전류는 25uA를 소모한다.

This paper describes a high PSRR low-dropout(LDO) linear regulator for wide frequency range without output-capacitor. Owing to both of the cascode compensation technique and the current buffer compensation technique in nested Miller compensation loop, the proposed LDO not only maintaines high stability but also achieves high PSRR over wide frequency range with reasonable on-chip capacitances. Since the external capacitor is removed by the proposed compensation techniques, the cost for pad is eliminated. The designed LDO works under the input voltage range from 2.5V to 4.5V and provides up to 10mA load current with the output voltage of 1.8V. The LDO was implemented with 0.18um CMOS technology and the area is 300um X 120 um. The measured power supply rejection ratio(PSRR) is -76dB and -43dB at DC and 1MHz, respectively. The operating current is 25uA.

키워드

참고문헌

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