| 摘要 |
PURPOSE:To prevent an IC card from being deformed due to heat by interrupting power supply at the time of detecting that temperature near the IC chip of the IC card exceeds a prescribed value or that a power supply level to the IC card exceeds a prescribed value. CONSTITUTION:The 1st abnormality detecting circuit 1 includes an overcurrent detecting circuit 1-1, and at the time of generating overcurrent, outputs a signal L, inverts the signal L to a signal H by an inverter 1-2, and inputs the signal H to an OR circuit 3-1. In the 2nd abnormality detecting circuit 2, a temperature sensor 2-1 arranged close to the IC chip detects temperature, when the output of the sensor 2-1 is higher than the voltage Vaa of a comparing voltage 2-2 is detected by a comparator 2-3, the comparator 2-3 outputs the signal H and inputs the signal H to the OR circuit 3-1. When an abnormal signal H is outputted from one of the 1stand 2nd circuits 1, 2, the output is informed to a host device 25 and an interruption switch 3-2 is opened to interrupt power supply to the IC card. Consequently, the IC card can be prevented from being deformed and an overcurrent due to a small flaw can be identified. |
