應用於可攜式產品之精準控制鋰電池充電器與臨界電壓控制之切換電容式直流轉換電路

Abstract

近年來，可攜式產品成了消費者最受歡迎的商品，而其市佔率也是急速的上升，可以說進入了手持式裝置的時代，而在手持式裝置幾乎都依賴電池的供電下，因此，如何有效的將能量從外界充到電池內以及針對各種電池的供應電壓進行電壓轉換也成了重要的課題。 本論文提出具有精準終止充電電路與類比式平滑轉換技術的鋰離子充電器和藉由臨界電壓交錯控制達成具有連續輸出穩壓功能的電容式倍壓電路。 在鋰離子充電器部分，對於一般的鋰離子電池定電壓定電流模式（CC-CV Mode）是現今最為廣泛使用的充電方法，本篇論文的定電壓定電流模式採四階段充電，細分為涓電流區域、定電流區域、定電壓區域和終止充電區域。透過具有精準終止充電電路及類比式平滑轉換技術的鋰離子電池充電器不但可以精準的將電池容量充滿也可以避免電池受充電損害以延長電池壽命。 在電容式倍壓電路部分，所提出的電荷汞穩壓電路可使用於有升壓需求的時候，而本篇論文提出了用臨界電壓去作調變的新機制並且採用交錯控制來達成連續的輸出端穩壓，藉此改善輸出端的穩壓及鏈波電壓。 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 recent years, portable products have become the most popular commodity for consumers, and its market share is rising rapidly. Because handheld devices rely on the power of battery, the energy charged to battery and the voltage conversion for a variety of batteries have become important issues. This paper presents a lithium-ion charger with accurate termination of the charging circuit and analog smooth conversion technology and a switched-capacitor DC-DC converter with dual branch interleaving regulation by threshold voltage switching. In the lithium-ion charger part, based on physical properties of battery cells, constant current and constant voltage mode （CC-CV Mode）is widespread use of a charging method. The charging model of this thesis is divided into four stages, which are trickle current（TC） stage, constant current（CC） stage, constant voltage（CV） stage ,and end of charge（EOC）stage. In addition, accurate charge termination circuit and analog smooth transition technology not only help to precisely reach the charging voltage but also avoid battery damage by overcharge to extend battery life. In the switched-capacitor voltage doubler part, the proposed charge pump regulator circuit can be used for boost demand. The thesis proposes a new mechanism with modulation of threshold voltage. This paper presents a new mechanism and an interleaving fashion to achieve continuous output voltage regulation, thereby improving the output voltage regulation and ripple voltage. The chips presented in this paper were fabricated by Taiwan Semiconductor Manufacturing Company （TSMC） 0.35μm 2P4M 3.3V mixed‐signal CMOS process.

Keywords: Lithium battery charger, accurate control, analog smooth transition, switched- capacitor voltage doubler, threshold voltage modulation.