具有電流模式平滑轉換電路之高效率切換式鋰電池充電器

Abstract

近年來，隨著可攜式產品的蓬勃發展以及電腦設備的微型化，再加上群眾對於可攜式產品的依賴性越來越高，使得可攜式產品的功能及規格要求也日漸提升，然而對可攜式3C產品而言，其供應能源大多需要仰賴於充電電池，因此如何有效率的將能量從外界儲存到電池中也成為近年研究發展的主流。 因此我們考量到現在產品的發展總是趨向於高效率、小體積、低成本以及高安全性的設計下，本論文提出具有電流模式平滑轉換電路之高效率切換式鋰電池充電器，我們利用電流模式平滑轉換電路以及漣波控制關閉時間電路，本著峰值電流偵測(Peak Current Control)、電流模式操作(Current Mode Operation)以及關閉時間控制(Off-time Control)三大概念的系統設計下，我們提出一較新型的切換式充電器系統控制架構，藉此降低電路複雜度、簡化頻率補償電路、提升整體效能以及保護充電器及電池的基本訴求，使得切換式鋰離子充電器在兼顧效能以及穩定度的應用上更為簡便，以追求更高效能更安全以及更低成本的產品設計。 當輸出端電池電壓為2.5伏特時，系統最高頻率為935.45k Hz，而電流在小電流模式時為201.8mA，大電流模式時為600.98mA，電池最終電壓被充至4.193伏特，系統平均效能為90.85%，在輸出電壓為2.5伏特及4伏特時，輸出電流漣波誤差最差值為7.15%，最後整體電路晶片面積為1.223mm×1.365mm。 本論文所呈現之晶片皆使用台積電所提供之0.35微米2P4M 的標準互補式金氧半製程來完成。

In the recent years, what make the specifications of the portable products become more and more rigorous are not only the development of portable products, but also the miniaturization of computer equipment and the dependence of human. However, for the portable products, the energy supply comes from the batteries, and that’s why how to charge the energy efficiently into the batteries becomes the main topic of the recent research. This thesis presents a Lithium Battery Switching Charger with Current Mode Smooth Transition Circuit and Ripple Controlled Off-time Circuit, relying on the consideration of the product development always tending to high-efficiency, small-size, low-cost, and high-safety standards. The new charging system is based on the three concepts of Peak Current Control, Current Mode Operation, and Off-time Control, Which will reduce the charger complexity, simplify the compensation circuits, improve the efficiency, and protect the charger and battery from damage. Therefore, we can pursuit higher efficiency, higher safety standards, and lower products cost by using the new type of the switching charger . When the output voltage is 2.5V, the highest operation frequency is 935.45k Hz. The current is 201.8mA in Trickle Current Mode, and 600.98mA in Constant Current Mode. The terminal battery voltage is 4.193V, and the efficiency is 90.85%. The ripple error is 7.15% in the worst case. The chips area is 1.223mm×1.365mm. The chips presented in this thesis were fabricated by Taiwan Semiconductor Manufacturing Company （TSMC） 0.35μm 2P4M 3.3V mixed‐signal CMOS process.