Patent ID: 8328103

Claim:
A transponder circuit including: (a) an antenna for receiving radio frequency signals; (b) an extraction unit for extracting from the radio frequency signals received by the antenna at least a part of energy necessary for powering the transponder circuit; (c) a non volatile memory unit; (d) a received energy evaluation unit; (e) a control logic unit for the transponder circuit, wherein the control logic unit is operably connected to send a write or programming instruction to the non volatile memory unit, and wherein the control logic unit activates the received energy evaluation unit when a write operation is received via the received radio frequency signals, wherein the evaluation unit is arranged directly at the antenna so as to provide the control logic unit with a first signal representative of a status of the energy available in the antenna indicating whether the available energy is greater than a minimum level for ensuring a proper write operation or whether the available energy is less than the minimum level for ensuring a proper write operation, wherein the control logic unit performs the write operation when the available energy is greater than the minimum level, and the control logic unit does not perform the write operation when the available energy is less than the minimum level, and the evaluation unit comprises a write operation simulation unit that includes i. a resistive divider; ii. a set of resistors arranged in parallel with the resistive divider, or a programmable current source; and iii. rectifier means on each connector of the antenna for simulating a write operation in the memory unit and for simulating energy recuperable by a power supply of the transponder circuit, wherein the rectifier means is operably connected to at least the resistive divider; and (f) a transponder circuit supply voltage monitoring unit that interrupts the received energy evaluation unit when a supply voltage of the transponder circuit is less than a predetermined transponder circuit operating threshold, wherein the transponder circuit supply voltage monitoring unit includes i. a voltage divider that returns the supply voltage to a level chosen to be comparable to a reference voltage; ii. a hysteresis comparator for selecting a reaction time for interrupting the received energy evaluation unit while a received energy evaluation is in progress; and iii. an interruption logic unit for switching on the received energy evaluation unit upon request and interrupting the received energy evaluation unit.