| 摘要 |
PROBLEM TO BE SOLVED: To provide a charger capable of eliminating the necessity of a highly precise comparator in detecting charging completion by a charging completion detecting current, and an individual reference voltage source. SOLUTION: The outputs of operational amplifiers AMP1 and AMP2 are supplied to a negative terminal and a positive terminal of a comparator 16, respectively to obtain judgement signals CC/CV indicating a constant current charging mode and a constant voltage charging mode from the comparator 16. A controller 11 generates control signals Is/Ic which become L at a charging completion detection period per constant cycle in the constant voltage charging mode. When the Is/Ic becomes L, a reference voltage supplied to the positive terminal of the operational amplifier AMP2 is a smaller value. The reference voltage of the positive terminal of the operational amplifier AMP2 is set so as to be a voltage value equal to a value corresponding to the charging completion current Is. When the CC/CV becomes H in the charging completion detecting period, charging completion is detected. COPYRIGHT: (C)2009,JPO&INPIT
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