| 摘要 |
PURPOSE: Provided are a charge control circuit capable of pulse charging secondary batteries such as lithium ion battery within a shorter period of time. CONSTITUTION: The charge control circuit (20) comprises a constant current circuit (21) for supplying a constant current to a second battery (40); a switch (SW1) for electrically connecting/disconnecting between the constant current circuit and the second battery; and a switch control circuit for supplying a pulse current to the second battery from the constant current circuit by repeatedly controlling on/off of the switch, wherein the switch control circuit varies a pulse width of the pulse current based on a battery voltage of the second battery, wherein the switch control circuit comprises a triangular wave generating circuit (23) for generating a triangular wave pulse voltage having certain cycle and amplitude and varies a pulse width of the pulse current based on the triangular wave pulse voltage and the battery voltage, wherein the switch control circuit further comprises an error amp (22) for generating an output voltage for showing a difference between the battery voltage and a reference voltage, and a comparator (24) for switching on or off the switch according to comparison results by comparing the output voltage of the error amp with the battery voltage, wherein the battery voltage has a voltage detection circuit (25) for switching off the switch by detecting that the battery voltage reaches a certain voltage, and wherein the voltage detection circuit is synchronized by a synchronizing signal from the switch control circuit to detect the battery voltage.
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