| 摘要 |
PROBLEM TO BE SOLVED: To improve the accuracy of a current value that starts overcurrent protection at charging and discharging, in an overcurrent protection circuit of a secondary battery. SOLUTION: In the overcurrent protection circuit that performs block control for an overcurrent by turning on/off switching elements on the basis of the overcurrent detection result of a detection means that detects the overcurrent, there are arranged for constituting the detection means that detects the overcurrent: comparison means (first and second comparators CMP1, CMP2) that compare a voltage drop in a high-accuracy detection resistor 3 connected to the switching elements (first and second switching elements M1, M2) in series therewith and predetermined reference voltages (first and second reference voltages Vs1, Vs2), respectively; and control means (inverters INV1 to 4) that turn off the switching elements (the first and the second switching elements M1, M2) when the voltage drop in the detection resistor 3 lowers below the reference voltages (the first and the second reference voltages Vs1, Vs2) in the comparison result of the comparison means, and block flowing currents by the switching elements (the first and the second switching elements M1, M2) and the detection resistor 3. COPYRIGHT: (C)2005,JPO&NCIPI
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