| 摘要 |
PROBLEM TO BE SOLVED: To use a small FET element of ON-resistance as the FET of a switching circuit for charge and discharge control. SOLUTION: This charge and discharge control of a secondary battery 10 are performed by turning on FETs 12 and 3 connected in series, and in a charge and discharge control circuit 102, in which the overcharge detection and the overcurrent detection are both performed through a resistor 10 for prevention of breakage in reverse contact, a threshold level Vs for detection if an overcurrent detection circuit 130 is raised, in the case that the overcharge condition has already been detected by an overcharge detection circuit 119. As a result, even of a through-current flows to the resistor 106 and the input level of the overcorrect detection circuit 130 is apparently raised when the FET 113 is turned off by overcharge detection, overcurrent detection is not performed. |
