| 摘要 |
PURPOSE:To provide the IC card detecting method which can detect the load of an IC card with low power consumption even when the load current of the IC card is considerably changed. CONSTITUTION:In the non-load state of unloading the IC card to a terminal equipment, a current mirror circuit 12 is turned off and the output of a comparator 13 is turned to 'L' level. In the load state of loading the IC card to the terminal equipment and letting a small current flow to the IC card, the current mirror circuit 12 is turned on, the comparator output is turned to 'H' level and the load of the IC card can be detected. In the load state of letting a large current flow to the IC card, the current mirror circuit 12 is turned on but since the current mirror circuit 12 is decided to the threshold of a small current, the current is branched to a current boost circuit Q23 and the output of the comparator 13 is turned to 'H' level so that the load of the IC card can be detected. |
