Abstract: 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.

Abstract: 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.

Abstract: A DC-DC converter includes a switch, a rectifier, a smoothing circuit, and a control circuit. The control circuit includes an output detection circuit for outputting an error signal, a current detection circuit for outputting a current detection signal in a period in which at least the switch is OFF, a first circuit for outputting a first signal for setting a timing of turning ON of the switch according to a comparison result between the error signal and the current detection signal, and a second circuit for outputting a second signal for setting an ON time of the switch, according to a reduction in output power from the smoothing circuit, so that the ON time of the switch is reduced, and generates the control signal, based on the first and second signals.