Patent ID: 7599661

Claim:
A method of determining disconnection time information which is significant for a disconnection period in which disconnection period an integrated circuit of a data carrier designed for contactless communication with a communication partner device has not been adequately supplied with power by a power supply field, the method comprising: charging at least one first storage capacitor of the integrated circuit while the integrated circuit is being adequately supplied with power; discharging the at least one first storage capacitor from a first starting time when the integrated circuit is subsequently no longer adequately supplied with power; determining the disconnection time information on the basis of the discharge behavior, which is affected by the IC material and by radiation, of the at least one first storage capacitor: and correcting the determined disconnection time information in dependence on the effects of at least one of the IC material and at least one radiation effect, and on the basis of the discharge behavior of the at least one first storage capacitor and on discharge behavior of a second storage capacitor of the integrated circuit, wherein a renewed charging of the at least one first storage capacitor is prevented from a second starting time following the first starting time, from which second starting time an adequate supply is re-established, to a determination time and wherein the second storage capacitor is charged from the second starting time and wherein the second storage capacitor is discharged from a third starting time following the second starting time and wherein the discharge voltage of the at least one first storage capacitor is compared to the discharge voltage of the second storage capacitor at the determination time following the third starting time and wherein the disconnection time information is determined in dependence on a result of the comparison.