應用於音頻之三角積分調變器之設計與製作

Abstract

類比數位轉換器(ADC)一直被大量應用於電子產品，隨著應用的不同，ADC的選擇及設計非常重要。目前的ADC 可分為Flash ADC、Pipeline ADC 和Sigma-Delta ADC 等，其中Sigma-Delta ADC 適合應用在低頻寬且需要高解析度的電子產品，而Sigma-Delta ADC 未來發展還是朝向高解析度、低功率消耗及低晶片製作成本的方向以提升效能。其中，信號頻帶在音頻的可攜式裝置，如mp3播放器及助聽所用的ADC，設計時多會考慮如何增加電池壽命，也就是降低功率消耗，及降低晶片面積，以方便攜帶且減少成本。 由於可攜式行動裝置的快速成長，電路操作在低電壓低功率已經是一種趨勢。我們在低功率的前提下，設計一個頻寬在音頻內，擁有高解析度、穩定度且製作成本低的Sigma-Delta ADC，應用於中輕度聽障者使用的助聽器，晶片面積0.058mm2，功率消耗53uW。

Analog-to-digital converters (ADCs) are employed in many electronic products, and it’s important to make a choice between accuracy and speed for different applications. In several kinds of ADCs (Ex: Flash ADC、Pipeline ADC and Sigma-Delta ADC), Sigma-Delta ADC is suitable for low speed and high resolution electronic products. The principles when designing Sigma-Delta ADC are high resolution 、low power consumption and low cost. The ADCs which are application for portable devices such as mp3 players and hearing aids would be designed for low power consumption and small chip area. Because of fast growing of portable devices, circuit operation with low-voltage and low-power is desirable. In the premise of low power consumption, we designed a Sigma-Delta ADC which is high resolution 、high stability and low cost. The ADC is employed in the hearing aids for moderately hearing-impaired. The chip area is 0.058mm2 and power consumption is 53uW.