||Design of Power Conversion Chips for Biomedical and Backlighting Applications
||Department of Electrical Engineering
Switched-capacitor DC-DC converter
step-up/step-down voltage conversion
and LED backlight
第一部分為低功耗電子系統電路的電源轉換器設計，其輸入電壓為1.8–5Ｖ，輸出電壓為3.3Ｖ，利用ㄧ升降壓型切換電容式電荷泵浦來實現。系統的穩定性則利用average space的分析方法加以探討並以切換電容架構來實現晶片內建補償器。所使用的製程為台灣積體電路公司0.35-μm 2P4M 5V混合訊號製程，使用的晶片面積為1.56x1.47mm2，線性調節率為64mV/V，負載調節率為0.793mV/mA。第二部分為數據監視器的背光源控制器設計，利用RGB-LED三原色來調節監視器的背光。實現的方法主要使用一切換式升壓轉換器與一電流平衡器來完成。所使用的製程為台灣積體電路公司0.25-μm BCD 1P5M高壓混合訊號製程，使用的晶片面積為1.9x1.7mm2。輸入電壓為8–12Ｖ，輸出電壓分別為13.5Ｖ(R-LED)、 20Ｖ(G-LED)、 21.5Ｖ(B-LED)。
In recent years, portable electronic products become increasingly popular. Hence, how to prolong the service time of portable electronic products is one of the most important issues. This dissertation focuses on the design of power management chips for low-power portable electronics, such as sphygmomanometers and wearable devices, and it is mainly composed of two topics.
The first topic is the design of a power converter for a low-power portable electronics, and the proposed switched-capacitor converter can work with the input voltage ranging from 1.8 V to 5V. Because the output voltage is set to 3.3V, it is actually a step up/down converter. Besides, the stability of the proposed converter is analyzed by use of average space analysis method. Furthermore, its compensator is built-in and implemented by using switched-capacitor circuits. The chip was implemented by using the TSMC 0.35μm 2P4M 5V mixed-signal polycide process, and the chip area is 1.56x1.47mm2. Its line regulation is 64 mV/V, and its load regulation is 0.793 mV/mA. The second topic is the design of a boost converter for driving the RGB-LEDs, which are used as the backlight of the monitor. A current balancer circuit is also included in the proposed chip, which was fabricated by using the 0.25-μm TSMC BCD 60V technology, and its area is 1.9 × 1.7 mm2. The input voltage is 8 - 12V, and the output voltages can be 13.5V (R-LED), 20V (G-LED), or 21.5V (B-LED).
Chapter 1 Introduction 1
1.1 Motivation 1
1.2 Dissertation Architecture 2
Chapter 2 Bandgap Reference Circuit Techniques 3
2.1 Design of Bandgap Circuits 3
2.2 Measured Results 9
2.3 Summary 15
Chapter 3 Switched-Capacitor DC-DC Converter for Biomedical Applications 16
3.1 Switched-Capacitor DC-DC Converter Topologies 16
3.2 Block Diagram and Main Circuits 16
3.2.1 Triple-Mode SC Power stage 17
3.2.2 Mode Selector 24
3.2.3 Feedback Circuit 25
3.2.4 Input-Voltage-Independent Clock Generator 31
3.2.5 Current-Mode Bandgap Reference Circuit 32
3.3 Measured Results 33
3.3.1 Input-Voltage-Independent Clock Generator 33
3.3.2 System Performance 34
3.4 Summary 40
Chapter 4 Boost DC-DC Converter for RGB-LED Backlight Application 42
4.1 Controlling methods of LED drivers 42
4.2 Block Diagram and Main Circuits 44
4.2.1 Low Dropout Linear Voltage Regulator (LDO) 44
4.2.2 Bandgap Reference Circuit 45
4.2.3 Current Balancing Circuit 49
4.2.4 PSM controller 51
4.3 Measured Results 52
4.4 Summary 54
Chapter 5 Conclusions and Future Work 55
5.1 Conclusions 55
5.2 Recommendations of Future Work 56
List of publication 65
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