本篇論文呈現一個應用於可攜式發電機的新型多重模式線性鋰離子電池充電器。由於鋰離子電池本身特性的關係,一般傳統充電器都會採用三個階段的充電模式:依序為小電流充電、大電流充電以及定電壓充電,也因為定電流充電的關係,充電器無法在定電流充電模式下改變自身的充電電流。然而可攜式發電機為一個不穩定的功率來源,如果可攜式發電機提供過多的功率輸出而使得後端充電器沒辦法消耗的話,這些多餘的能量會全部浪費在前端的可攜式發電機中,因此本論文將傳統的系統改良成應用於可攜式發電機的新型多重模式線性鋰離子電池充電器,此系統可以動態的偵測浪費在前端可攜式發電機中的電流,並轉換這些浪費掉的電流成為充電電流,充電器也會因為減少了這些無法吸收的電流進而提升整體的充電效率。 本論文使用TSMC 0.35 m CMOS 2P4M標準製程來實現充電器晶片,量測結果顯示:如果用可攜式發電機提供電源的話,使用本充電器來進行充電會使充電效率從32.3%增加到55%。
This thesis presents a new multi-mode linear Li-ion battery charger for portable generators application. Traditionally, based on the physical properties of the battery cell, charger circuits charge cells with three modes, which are the trickle current mode (TC), the constant current mode (CC), and the constant voltage (CV) mode. In the constant current mode, the charging current of chargers is fixed. However, the portable generator provides varying output power to the charger. If the portable generator provides too much power that the charger IC cannot handle and pass on, the excess power can only be wasted in the portable generator itself. In this thesis, the new multi-mode Li-ion battery charger for portable generators application can dynamically detect the charging output current of the portable generator and efficiently convert the current into the charging current. Compared with the original CC mode operation, the charger in this work can improve the power efficiency. The IC was fabricated in TSMC 0.35 m CMOS technology. The experiment shows that the power efficiency can be improved from 32.3% to 55%.