| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protection circuit capable of interrupting a current of a secondary battery even if a short overcurrent detection period continues. <P>SOLUTION: The protection circuit includes: overcurrent detection portions RS, 35, 36, R21 and R22 detecting an overcurrent from a voltage generated by a flow of the current in the secondary battery in a current detection resistor and outputting an overcurrent detection signal; overcurrent period determination portions C1, 37 to 41, 44, 45, I21 and SW21 to SW23 integrating an overcurrent period when the overcurrent is detected from the overcurrent detection signal and interrupting the current of the secondary battery when an overcurrent period integrated value exceeds prescribed overcurrent detection delay time; and non-overcurrent period determination portions C2, 41, 42, 47 to 49, I22 and SW24 to SW26 integrating a non-overcurrent period when a non-overcurrent is detected from the overcurrent detection signal and initializing the overcurrent period integrated value when a non-overcurrent period integrated value exceeds prescribed restoration delay time and releasing current interruption of the secondary battery. <P>COPYRIGHT: (C)2012,JPO&INPIT |
