隨著可攜式電子產品的發展與盛行，低功率高效率成為可攜式電子產品的首要考量，因此這些利用電池提供電源的電子電路必須工作在低電壓低電流以降低能量消耗，使得電池可以長時間的工作。此外，在製程技術不斷進步的同時，由於可靠度的考量，其工作電壓也必須隨著製程進步而降低，為了節省功率的消耗，穩壓器常被用來降低工作電壓。 本論文提出的電流型降壓切換式穩壓器，其原理主要是利用偵測電感上電流變化以加速因負載改變時之暫態反應時間，根據電路回授機制將輸出電壓控制在所預期的數值，而不會受到負載電流的差異影響。相較於電壓模式控制，電流模式控制降壓式穩壓器具有較好的負載調節度、線性調節度及較快的暫態反應。而切換式穩壓器本身轉換效能高，因此適用於可攜式電子產品中。 此電流型降壓切換式穩壓器是以台灣積體電路製造股份有限公司0.18um 3.3V互補式金氧半製程來實現，而工作電壓的範圍為2.4V~4.6V，操作頻率為0.7MHz~1.4MHz，負載電流範圍為0.05A~0.5A，及轉換效能為91.16%。此電流型降壓切換式穩壓器線性調節度與負載調節度分別為6.27mV/V 與0.0107mV/mA，而其核心面積為0.711mm2。 The fast growing demand of portable and battery-operated electronic systems has driven the efforts to reduce power consumption or to improve the efficiency of these electronic equipments. Regulators are essential for most electrically powered systems which include the prevalent portable equipments. Regulators are required to reduce the voltage variations of the battery. Besides, regulators are often utilized to provide a lower voltage from a higher input voltage for power reduction. Current trend in portable or battery-powered electronics demands ultra-low-power consumption or high operating efficiency to prolong the service time of these battery-operated equipments. In this thesis, the proposed current mode buck converter senses the inductor current variation to accelerate response time, and applies the mechanism of feedback-loop theory to control the output voltage at the desired value. Compared with the voltage mode buck converter, the current mode buck converter has better load regulation, better line regulation and faster transient response. The proposed buck converter has high efficiency, and, therefore, it is suitable for the application of portable products. This current mode switching regulator is fabricated with TSMC 0.18um 3.3V CMOS process. In the proposed buck converter, the operation voltage is form 2.4V to 4.6V, the loading current is form 0.05A to 0.5A, and the efficiency is 91.16%. The line regulation and load regulation are 6.27mV/V and 0.0107mV/mA respectively. The core area is 0.711mm2.
