| 摘要 |
There is provided a charging apparatus that, even when an AC adapter is connected and there is heavy load, makes it possible to reduce heat produced due to the power loss of a control transistor, reduce cost and area for implementation, and improve safety. Charging apparatus 100 has: P-channel MOS transistors M1 and M2 that control charging current; current detecting resistance Rs that is connected to current output terminals of P-channel MOS transistors M1 and M2 and detects the charging current; switch 130 that is arranged on a path that bypasses current detecting resistance Rs; and load 300 that receives power supply from battery 200 without involving current detecting resistance Rs when switch 130 is closed. Current difference amplifier 120 amplifies the detected voltage of current detecting resistance Rs, comparator 160 compares the output voltage of current difference amplifier 129 with the reference voltage, and thereby, when current flowing into battery 200 is equal to or less than a predetermined value, switch 130 is closed and current detecting resistance Rs is short-circuited.
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