대한전자공학회논문지SD (Journal of the Institute of Electronics Engineers of Korea SD)

대한전자공학회 (The Institute of Electronics and Information Engineers)
권호 표지

1-비트 4차 델타-시그마 변조기법을 이용한 D급 디지털 오디오 증폭기

Class-D Digital Audio Amplifier Using 1-bit 4th-order Delta-Sigma Modulation

  • 강경식 (한양대학교 전자컴퓨터공학) ;
  • 최영길 (한양대학교 전자컴퓨터공학) ;
  • 노형동 (한양대학교 전자컴퓨터공학) ;
  • 남현석 (한양대학교 전자컴퓨터공학) ;
  • 노정진 (한양대학교 전자컴퓨터공학)
  • Kang, Kyoung-Sik (Dep. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Choi, Young-Kil (Dep. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Roh, Hyung-Dong (Dep. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Nam, Hyun-Seok (Dep. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Roh, Jeong-Gin (Dep. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University)
  • 발행 : 2008.03.25
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초록

본 논문에서는 휴대용 오디고 제품의 헤드폰 구동을 위한 델타-시그마 변조기법 기반의 D급 증폭기를 제안한다. 제안된 D급 증폭기는 고성능 단일 비트 4차 델타-시그마 변조기를 이용하여 펄스폭 변조 신호를 발생시킨다. 높은 신호 대 잡음비를 얻는 것과 동시에 시스템의 안정성 확보를 위하여 시뮬레이션을 통해 변조기 루프필터의 폴과 제로를 최적화하였다. 테스트 칩은 $0.18{\mu}m$ CMOS 공정으로 제작되었다. 칩 면적은 $1.6mm^2$ 이며, 20Hz 부터 20kHz까지의 신호대역을 대상으로 동작한다. 3V 전원전압과 32옴의 로드를 사용하여 측정된 출력은 0.03% 이하의 전고조파 왜율을 갖는다.

In this paper, we present the design of delta-sigma modulation-based class-D amplifier for driving headphones in portable audio applications. The presented class-D amplifier generates PWM(pulse width modulation) signals using a single-bit fourth-order high-performance delta-sigma modulator. To achieve a high SNR(signal-to-noise ratio) and ensure system stability, the locations of the modulator loop filter poles and zeros are optimized and thoroughly simulated. The test chip is fabricated using a standard $0.18{\mu}m$ CMOS process. The active area of the chip is $1.6mm^2$. It operates for the signal bandwidth from 20Hz to 20kHz. The measured THD+N(total harmonic distortion plus noise) at the $32{\Omega}$ load terminal is less than 0.03% from a 3V power supply.

키워드

참고문헌

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