Abstract
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%.