Patent ID: 8493034
Filing Date: 2013-07-23
Classification: H02J

Abstract:
1. A charge control circuit, comprising: a plurality of resistor groups connectable to a thermistor for measuring a temperature of a battery; a first switching unit that connects resistors in the resistor groups having different resistances in series to the thermistor; a comparator that obtains a node voltage at a connection node of the resistors and thermistor and outputs a comparison result of the node voltage and a reference voltage; a second switching unit that supplies the comparator with a temperature reference voltage and an attachment reference voltage; and a control unit that controls the first and second switching units and controls charging of the battery based on the comparison result; wherein the control unit performs a temperature scan that sequentially repeats a temperature estimation process, which connects the resistors having different resistances in the first switching unit, supplies the comparator with the temperature reference voltage from the second switching unit, and obtains the comparison result; and the temperature scan includes, between the temperature estimation processes, an attachment detection process for a plural number of times, in which the attachment detection process supplies the comparator with the attachment reference voltage and compares the voltage at the connection node with the attachment reference voltage, and wherein the second switching unit performs the attachment detection process using two attachment reference voltages in accordance with a connection state of the resistors in the first switching unit.