Journal of IKEEE (전기전자학회논문지)

Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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The Incremental Delta-Sigma ADC for A Single-Electrode Capacitive Touch Sensor

단일-극 커패시터 방식의 터치센서를 위한 Incremental 델타-시그마 아날로그-디지털 변환기 설계

  • Jung, Young-Jae (Dept. of Electronics and Communication Engineering, Hanyang University) ;
  • Roh, Jeong-Jin (Dept. of Electronics and Communication Engineering, Hanyang University)
  • Received : 2013.06.13
  • Accepted : 2013.07.02
  • Published : 2013.09.30
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Abstract

This paper presents an incremental delta-sigma analog-to-digital converter (ADC) for a single-electrode capacitive touch sensor. The second-order cascade of integrators with distributed feedback (CIFB) delta-sigma modulator with 1-bit quantization was fabricated by a $0.18-{\mu}m$ CMOS process. In order to achieve a wide input range in this incremental delta-sigma analog-to-digital converter, the shielding signal and the digitally controlled offset capacitors are used in front of a converter. This circuit operated at a supply voltage of 2.6 V to 3.7 V, and is suitable for single-electrode capacitive touch sensor for ${\pm}10-pF$ input range with sub-fF resolution.

본 논문에서는 단일-극 커패시터 방식의 터치센서를 위한 incremental 델타-시그마 아날로그-디지털 변환기를 설계하였다. 델타-시그마 모듈레이터의 구조는 단일비트 2차 cascade of integrators with distributed feedback(CIFB)를 사용하였으며 $0.18-{\mu}m$ CMOS 공정을 이용하여 제작하였다. Incremental 델타-시그마 아날로그-디지털 변환기의 입력으로 이어지는 센서가 넓은 입력 범위를 얻고 높은 정확성을 가지도록 변환기 앞에 shielding 신호와 디지털적으로 조절 가능한 오프-셋 커패시터를 위치시켰다. 본회로의 공급전압은 2.6 V에서 3.7 V이며 ${\pm}10-pF$의 입력범위를 가지고 fF 이하의 해상도를 필요로 하는 단일-극 커패시터 방식의 터치센서에 적합하다.

Keywords

References

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