本論文提出低輸出電壓漣波之降壓轉換器，此電路提出自適應峰值電流控制技術使降壓轉換器根據負載電流改變儲存的電感電流峰值，可有效改善固定導通時間控制方式在輕載輸出電壓漣波過大的問題，能將負載電流1-200mA範圍內的電壓漣波抑制至30mV內，在負載電流為1mA時，輸出電壓漣波僅10.8mV。再者，提出負載暫態響應改善技術，能改善降壓轉換器由輕載轉換至重載時的undershoot及recovery time，當負載電流由1mA改變至200mA時，降壓轉換器僅有23mV之undershoot和14µs的Recovery time。另外，本論文所提出的降壓轉換器電路，透過近零電流控制器防止逆向電感電流造成的傳導損失，改善降壓轉換器操作在輕載時的轉換效率，並提出抗振鈴電路可防止降壓轉換器操作在不連續導通模式之死區階段時，在電感和上、下橋開關之連接處產生的振鈴現象，避免電磁干擾相關問題。本論文所提之技術使用TSMC 0.18-μm 1P6M CMOS之製程實現，輸入電壓為3.3V，輸出電壓為1.5V，可供應負載範圍為1-200mA，最高轉換效率為96.7%，晶片的使用面積為0.58µm2。

This paper designs and implementation of a buck converter with low output voltage ripple. The circuit proposed an adaptive peak current control technique which enables the buck converter to store different peak inductor current according to load currents. Compared to the constant on-time control method, the adaptive peak current control technique can effectively improve large output voltage ripple issues in light load. The voltage ripple in the load current range of 1-200mA is suppressed within 30mV. When the load current is 1mA, the output voltage ripple is only 10.8mV. Furthermore, a load transient response improvement technique is proposed, which can improve the undershoot and recovery time of the buck converter when load current switch from light load to heavy load. The buck converter only has 23mV undershoot and 14µs recovery time when the load current is changed from 1mA to 200mA. The proposed buck converter improves the conversion efficiency in light load by adding a near-zero current controller to prevent conduction losses caused by reverse inductor current. Ringing killer circuit prevents the buck converter operated in the dead-time period to occur ringing effect at the junction of the inductor and the two power transistors. The proposed buck converter was fabricated by using TSMC 0.18-μm 1P6M CMOS process. The input voltage is 3.3V, the output voltage is 1.5V, and the load current range is 1-200mA, the maximum efficiency is 96.7%, the area of the chip is 0.58µm2.

摘要.....................................i
Abstract.................................ii
誌謝.....................................iii
目錄.....................................iv
表目錄...................................vi
圖目錄...................................vii
第一章 緒論...............................1
1.1研究背景...............................1
1.2研究動機...............................1
1.3論文架構...............................2
第二章 降壓轉換器輸出電壓漣波探討............3
2.1 DCM輸出電壓漣波分析....................3
2.1.1儲能階段.............................3
2.1.2釋能階段.............................5
2.1.3死區階段.............................6
2.2輸出電容ESL、ESR分析....................7
2.2.1儲能階段.............................8
2.2.2釋能階段.............................9
2.2.3死區階段.............................9
2.3低輸出電壓漣波之降壓轉換器設計要點........11
第三章 具低輸出電壓漣波之降壓轉換器..........13
3.1脈波頻率調變之降壓轉換器.................14
3.1.1峰值電流感測器........................14
3.1.2關閉時間產生電路......................17
3.1.3脈波頻率調變控制器....................18
3.1.4模擬結果.............................21
3.2自適應峰值電流控制技術...................23
3.2.1降壓轉換器工作週期分析.................23
3.2.2自適應峰值電流控制器...................25
3.2.3限制電壓電路..........................30
3.2.4實驗結果..............................32
3.3負載暫態響應改善技術.....................39
3.3.1降壓轉換器負載暫態響應.................40
3.3.2負載電流偵測器........................41
3.3.3峰值電流感測器........................44
3.4實驗結果...............................45
3.4.1模擬結果.............................45
3.4.2量測結果.............................48
3.4.3整體電路效能.........................52
第四章 具輕載效率改善功能電路...............53
4.1降壓轉換器效率分析......................54
4.2降壓轉換器之逆向電感電流探討.............57
4.3近零電流控制器.........................59
4.3.1近零電流感測器.......................59
4.3.2不連續導通模式控制器..................62
4.3抗振鈴電路.............................63
4.3.1振鈴現象.............................63
4.3.2抗振鈴電路動作說明....................65
4.4降壓轉換器實驗結果......................68
4.4.1模擬結果.............................68
4.4.2量測結果.............................70
第五章 結論...............................74
參考文獻..................................75
Extended Abstract........................77

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