摘要：
本篇論文討論的是可對身體訊號取樣的一個取樣系統，傳統上應用於心電圖上的記錄。
提出的系統可以依照當時信號的內容來使用兩種不同的取樣頻率進行取樣：如果信號的內容
有較大的電壓振幅變化則採用較高的取樣頻率來取樣；而在較小的電壓振幅變化的區間則採
用較慢的取樣頻率用以節省記憶體跟功率。此類比控制器會依據輸入信號決定用較高或較慢
的取樣頻率來取樣。在此篇論文中會詳細介紹此系統的概念，而且使用PCB驗證概念的可行
性。由PCB所得到的資料發現可以節省50%的平均取樣頻率及35%的資料傳輸率。而此提出
的系統可晶片化於0.35μm的製程。量測資料用於確定相關電路設計的功能。

Abstract:
This thesis is concerned with the acquisition of body signals using a sampling system. A typical
application is the recording of the electrocardiogram (ECG). It is proposed to sample the input
signal at different rates, depending on the momentary signal content. If the input signal has large
voltage variation, it is sampled at a high rate. During periods of small variation, the signal is
sampled at a lower frequency to save both memory and power. An analog controller to control the
clock rate is proposed and implemented. The analog controller decides the sample frequency (high
rate or low rate) depending on the input signal. The analysis of the proposed system is presented in
this thesis. Furthermore, a working prototype is implemented using discrete components on a PCB.
The measured results show a significant reduction in the average sample frequency and data rate of
50% and 35%, respectively. Finally, the critical analog circuit blocks of the system suitable for
integration on chip are proposed and implemented in a 0.35μm CMOS process. Measured results
are reported to confirm the functionality of the blocks.

1 INTRODUCTION TO ECG: 1
1.1 A brief introduction of ECG figures: 1
1.2 The idea of sensor ECG: 2
2 BRIEF CONCEPT OF THE ANALOG CONTROLLER SCHEME: 7
2.1 Property of derivative and two conditions: 7
2.2 Block diagram of comparators: 8
2.3 Logic circuit parts: 9
2.4 Laplace transform and high pass filter: 11
3 CIRCUIT ON PCB: 13
3.1 Brief introduction to PCB and noise: 13
3.2 The MF4 digital filter setting: 13
3.3 High pass filter and block diagram: 14
3.4 Reference voltage generation: 14
3.5 Alternative connection of comparator inputs and logic gate: 15
3.6 PCB Measured Results: 17
3.6.1 Problems of interference and proposed solution: 18
4 THE SYSTEM DESIGN: 22
4.1 The large time constant circuit: 22
4.1.1 The transfer function 23
4.1.2 Noise analysis and frequency response 25
4.1.3 Compare the noise of the two structures 30
4.1.4 The gm circuit design 32
4.2 The circuit of the system 38
4.2.1 Brief concept of design circuit: 38
4.2.1.1 Two stage operational amplifier (Amp1): 38
4.2.1.2 Two stage operational amplifier (Amp2): 41
4.2.1.3 Comparison-threshold generation 42
4.2.2 The components in integrated circuit: 43
4.2.3 Resistor layout: 45
4.2.4 Capacitor in integrated circuit: 46
4.3 Chip layout: 47
5 MEASUREMENT RESULTS: 48
6 CONCLUSION: 52
REFERENCES: 53
7 LIST OF PUBLICATIONS RESULTING FROM THIS WORK: 53

References:
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