Abstract:
A method for evaluating the current coupling factor between an electromagnetic transponder and a terminal, wherein a ratio between data representative of a voltage across an oscillating circuit of the transponder and obtained for two pairs of inductive and capacitive values of this oscillating circuit is compared with one or several thresholds, the two pairs of values preserving a tuning of the oscillating circuit to a same frequency.
Abstract:
An antenna generating an electromagnetic field for an electromagnetic transponder and a terminal provided with such an antenna. The antenna comprises a first inductive element designed to be connected to two terminals employing an energizing voltage, and a parallel resonant circuit coupled with the first inductive element.
Abstract:
A power supply circuit and a transponder having a circuit for rectifying an A.C. voltage and two power storage elements, the rectifying circuit providing a rectified voltage to at least one of the storage elements and an output voltage being provided by at least one of the storage elements, and at least one switching element for switching the circuit operation between a state of provision of a relatively high voltage and a state of provision of a relatively low voltage, the second state configuring the rectifying circuit in halfwave operation.
Abstract:
A method for protecting at least one first datum to be stored in an integrated circuit, including, upon storage of the first datum, performing a combination with at least one second physical datum coming from at least one network of physical parameters, and only storing the result of this combination, and in read mode, extracting the stored result and using the second physical datum to restore the first datum.
Abstract:
The invention concerns a circuit (1) for storing a binary code (B1, B2, Bi-1, Bi, Bn-1, Bn) in an integrated circuit chip, comprising an input terminal (2) applying a signal (E) triggering reading of the code, output terminals (31, 32, 3i-1, 3i, 3n-1, 3n) for delivering said binary code, first electrical paths (P1, P2, Pi, Pn) individually connecting said input terminal to each output terminal, each path inputting a fixed delay in the manufacture of the integrated circuit, and means (4, 51, 52, 5i, 5n) simultaneously integrating the binary states present in output of the electrical paths.
Abstract:
A method and a circuit for generating a secret quantity based on an identifier of an integrated circuit, in which a first digital word is generated from a physical parameter network, and this first word is submitted to at least one retroaction shift register, the output of the shift register forming the secret quantity.
Abstract:
The invention concerns an identification method and circuit (1) of the network type of parameters contained in an integrated circuit chip, comprising a single input terminal (2) for applying a signal (E) triggering an identification, the output terminals (31, 32, 3i−1, 3i, 3n−1, 3n) adapted to deliver a binary identifying code (B1, B2, Bi−1, Bi, Bn−1, Bn), first electrical paths P1, P2, Pi, Pn), individually connecting said input terminal to each output terminal, and means (4, 51, 52, 5i, 5n) for simultaneously integrating the binary states present in output of the electrical paths, each path inputting a delay sensitive to technological dispersions and/or of the integrated circuit fabrication method.
Abstract:
A memory cell with at least two detectable states among which is an unprogrammed state, comprising, in series between two terminals of application of a read voltage, at least one first branch comprising: a pre-read stage comprising, in parallel, two switchable resistors having different values with a first predetermined difference; and a programming stage formed of a polysilicon programming resistor, a terminal of the programming resistor being accessible by a programming circuit capable of causing an irreversible decrease in its value.
Abstract:
A terminal for generating an electromagnetic field adapted to communicating with at least one transponder, and a method for controlling such a terminal including: an oscillating circuit adapted to being excited by a remote supply signal of the transponder; a phase demodulator for detecting possible data transmitted by the transponder; circuitry for regulating the signal phase in the terminal's oscillating circuit on a reference value; circuitry for measuring variables linked to the current in the oscillating circuit and to the voltage thereacross; and circuitry for comparing current values of these variables with predetermined values, to determine the presence of a transponder.
Abstract:
A method for controlling an electromagnetic field generation terminal using a signal for exciting an oscillating circuit, provided with circuitry for regulating the signal phase in the oscillating circuit, including comparing current values of variables linked to the current in the oscillating circuit and to the voltage thereacross with predetermined values, to detect the presence of a transponder in the electromagnetic field.