此三角積分調變器使用台積電0.18 um 1P6M CMOS電路技術來實現，在訊號頻寬10 KHz、超取樣率為128倍的情形下，二階輸出SNDR可以達到82.79 dB，具有13.4位元的解析度。在1.8V電壓供給下平均功率消耗為109 µW，有效達到低功率的要求，未來結合後端數位降頻濾波器的實現，將類比與數位電路共同整合，將得以實現混合訊號處理三角積分類比數位轉換器晶片。 關鍵字: 三角積分調變器、切換式電容電路、類比數位轉換器 ;Abstract In recent years, biomedical measurement instruments have been used commonly in daily life. In order to achieve micro-size and longtime wearing, high resolution and low power consumption are the necessary factors of analog to digital converter (ADC). The sigma-delta modulator (SDM) ADC for biomedical signals was implemented in this paper. Compared to other types of ADC, the specification of SDM is simple and high tolerance. The SDM ADC also significantly reduces the chip area and power consumption, thus we designed a second-order sigma-delta modulator using switched-capacitor circuits This circuit was implemented in TSMC 0.18µm 1P6M CMOS process. With the signal bandwidth of 10 KHz and over-sampling ratio of 128, the signal to noise and distortion ratio (SNDR) can achieve 82.79 dB, 13.4 bits resolution, and power consumption is about 109 µW for 1.8 V power supply. The design will combine with the digital decimation filter to achieve mixed signal chip for sigma-delta analog to digital converter used in biomedical signal systems in the future. Keywords: sigma-delta modulator, switched-capacitor circuits, analog to digital converter (ADC)
