應用於藍芽與電子耳系統之連續時間三角積分類比數位轉換器設計

Abstract

本篇論文中，我們將分別設計適用於藍芽系統與電子耳系統的連續時間類比數位轉換器。

應用於藍芽系統的設計是一個三階、連續時間三角積分調變器，取樣頻率為64MHz，訊號頻寬1MHz，OSR為32，使用兩位元flash量化器。由量測結果可得50.325dB動態範圍，及48.2dB的最大訊號雜訊與失真比(SNDR)。晶片使用台積電180奈米製程，佈局面積為1.597 x 1.728 mm2。文中將顯示這顆晶片的模擬結果、佈局圖與量測結果。

應用於電子耳系統的設計是一個三階、連續時間三角積分調變器，取樣頻率為2.56MHz，訊號寬20KHz，OSR為64，使用三位元flash量化器。文中將顯示這個系統的模擬結果與佈局圖。由post layout simulation的結果，可得知74.9dB的訊號雜訊與失真比。晶片將以台積電180奈米製程製作，晶片面積為1.861 x 1.2 mm2，在1.8v的供應電壓下消耗功率約為6.13 mw。

文中一共提出兩顆不同規格的IC，一顆運作於中頻訊號，一顆運作於低頻訊號，雖然兩者都使用三階的連續時間三角積分調變器，但在實際的設計考量上卻需要以不同的觀點來思考，其主要目的是希望能對三角積分調變器的特性能更深入地了解。

In this thesis, the design of the A/D converters for applications of the Bluetooth system and the cochlear prosthesis will be introduced.

For the Bluetooth system, a third-order continuous-time delta-sigma modulator (CT-DSM) with 64MHz sampling rate, 1MHz signal bandwidth, OSR of 32, and a two-bit flash quantizer has been designed. It appears that the ADC achieves a dynamic range of 50.325dB and a peak signal to noise and distortion ratio of 48.2dB. The IC was fabricated in TSMC 0.18-m CMOS process with an active area of 1.597 x 1.728 mm2. For Cochlear Prosthesis, a third-order continuous-time delta-sigma modulator was also designed. The sampling rate is set to 2.56 MHz with 20 KHz signal bandwidth, the OSR equals 64, and a three-bit flash quantizer is used. Both simulation results and layout will be presented. The post-layout simulation shows that it achieves a peak signal to noise distortion ratio of 74.9 dB, and it dissipates about 6.13mw for 1.8V supply voltage. It will be fabricated in TSMC 0.18-m CMOS process with an active area of 1.861 x 1.2 mm2.

We will present two ICs with different specifications. One of them operates in the intermediate frequency, and the other in the low frequency. Although they are both the 3rd-order continuous-time delta-sigma modulators, they were designed in different points of view to enhance the understanding of the characteristics of the CT-DSM.