Abstract: In some embodiments, a contactless communication device includes an antenna, and a driving stage having a power supply terminal configured to receive a power supply voltage, where the driving stage is configured to deliver a current to the antenna. The device further includes a monitoring circuit configured to monitor the power transmitted by the antenna. The monitoring circuit is configured, in the presence of a request for a reduction in a current level of transmitted power, to reduce the power supply voltage of the driving stage down to a target value corresponding to a new level of the transmitted power less than the current level.

Abstract: A near field communication (NFC) method includes activating an NFC device second device in response to a first electromagnetic field generated by a nearby NFC device. The NFC device generates a second electromagnetic field after being activated. The first NFC device can detect the second electromagnetic field and initiate a near field communication process.

Abstract: A method can be used for detecting a potential presence of an object by a reader capable of mutually communicating via a contactless communications protocol. An antenna of the reader transmits a magnetic field on a carrier signal having a sub-carrier modulated by a first data sequence. The modulated sub-carrier is non-interpretable by the object. The antenna of the reader receives a signal resulting from the transmission. The reader demodulates the sub-carrier of the resulting signal so as to extract a second data sequence from the resulting signal. The first data sequence and second data sequence are correlated and the potential presence or absence of the object is determined based upon the result of the correlating.

Abstract: The invention relates to a device for protecting a near field communication router against possible over-voltages picked up by an antenna. The device includes two voltage-limiter elements between terminals of the antenna and a ground. A circuit detects the presence of an electromagnetic field in the vicinity of an operating frequency of the router, and controls the limiter elements, the limiter elements being active by default.

Abstract: An electronic device includes an antenna, an irremovable component, a removable component, an impedance matching circuit, and a controller. The impedance matching circuit is arranged in a first configuration corresponding to the removable component connected to the irremovable component. The impedance matching circuit has a first capacitor, a second capacitor, and a third capacitor. The controller is configured to arrange the impedance matching circuit in a second configuration corresponding to the removable component being disconnected from the irremovable component.

Abstract: A method can be used for detecting a potential presence of an object by a reader capable of mutually communicating via a contactless communications protocol. An antenna of the reader transmits a magnetic field on a carrier signal having a sub-carrier modulated by a first data sequence. The modulated sub-carrier is non-interpretable by the object. The antenna of the reader receives a signal resulting from the transmission. The reader demodulates the sub-carrier of the resulting signal so as to extract a second data sequence from the resulting signal. The first data sequence and second data sequence are correlated and the potential presence or absence of the object is determined based upon the result of the correlating.

Abstract: A contactless component, connected to an antenna, includes a plurality of terminals and a first, second, third, and fourth plurality of switchable auxiliary capacitors. The plurality of terminals include a first output terminal, a second output terminal, a first auxiliary terminal, and a second auxiliary terminal. Each of the first plurality of switchable auxiliary capacitors is connected between the first auxiliary terminal and the first output terminal. Each of the second plurality of switchable auxiliary capacitors is coupled between the first auxiliary terminal and a neutral point. Each of the third plurality of switchable auxiliary capacitors is coupled between the second auxiliary terminal and the second output terminal of the contactless component. Each of the fourth plurality of switchable auxiliary capacitors is coupled between the second auxiliary terminal and the neutral point.

Abstract: A system includes an antenna, and a contactless component for receiving and/or transmitting information via the antenna according to a contactless communications protocol. An inductive-capacitive network is connected between the antenna and the contactless component and includes a configurable filter for filtering electromagnetic interference. A processor modifies an impedance of the configurable filter for filtering electromagnetic interference to control frequency tuning of the antenna.

Abstract: An electronic device includes an antenna, an irremovable component, a removable component, an impedance matching circuit, and a controller. The impedance matching circuit is arranged in a first configuration corresponding to the removable component connected to the irremovable component. The impedance matching circuit has a first capacitor, a second capacitor, and a third capacitor. The controller is configured to arrange the impedance matching circuit in a second configuration corresponding to the removable component being disconnected from the irremovable component.

Abstract: A first component (CMP1) is connected to the antenna (ANT) and to an impedance matching circuit (CAI) configurable on command and connected to the antenna, and in the absence of another component (CMP2) connected to the antenna, the impedance matching circuit is placed in a first configuration in which it forms with the first component and the antenna a resonant circuit having a first resonant frequency compatible with a carrier frequency. In the presence of a second component (CMP2) connected to the antenna, the impedance matching circuit is placed in a second configuration in which it forms with the first component, the second component and the antenna a resonant circuit having a second resonant frequency compatible with the carrier frequency.

Abstract: An antenna circuit for a device of transmission/reception by inductive coupling, including a first inductive element in parallel with a capacitive element and, between each node of the parallel association and two terminals of a switch, a second inductive element.

Abstract: A system includes an antenna, and a contactless component for receiving and/or transmitting information via the antenna according to a contactless communications protocol. An inductive-capacitive network is connected between the antenna and the contactless component and includes a configurable filter for filtering electromagnetic interference. A processor modifies an impedance of the configurable filter for filtering electromagnetic interference to control frequency tuning of the antenna.

Abstract: A first component (CMP1) is connected to the antenna (ANT) and to an impedance matching circuit (CAI) configurable on command and connected to the antenna, and in the absence of another component (CMP2) connected to the antenna, the impedance matching circuit is placed in a first configuration in which it forms with the first component and the antenna a resonant circuit having a first resonant frequency compatible with a carrier frequency. In the presence of a second component (CMP2) connected to the antenna, the impedance matching circuit is placed in a second configuration in which it forms with the first component, the second component and the antenna a resonant circuit having a second resonant frequency compatible with the carrier frequency.

Abstract: A first component (CMP1) is connected to the antenna (ANT) and to an impedance matching circuit (CAI) configurable on command and connected to the antenna, and in the absence of another component (CMP2) connected to the antenna, the impedance matching circuit is placed in a first configuration in which it forms with the first component and the antenna a resonant circuit having a first resonant frequency compatible with a carrier frequency. In the presence of a second component (CMP2) connected to the antenna, the impedance matching circuit is placed in a second configuration in which it forms with the first component, the second component and the antenna a resonant circuit having a second resonant frequency compatible with the carrier frequency.

Abstract: An electromagnetic transponder includes an oscillatory circuit, a battery and a first rectifier bridge. Alternating current input terminals of the rectifier bridge are connected to the terminals of the oscillatory circuit, and at least two rectifier elements of the rectifier bridge are controllable on the basis of the voltage supplied by the battery.

Abstract: An NFC component includes a first interface that can be used in reader mode and is configured to be connected to an antenna via an impedance matching external circuit. A second interface can be used in card mode and in reader mode and is configured to be connected to the antenna and to the first interface via the impedance matching external circuit. An internal module includes a first detection circuit configured to deliver a first detection signal that represents the phase antenna matching quality when the impedance matching external circuit and the antenna are indeed connected between the first interface and the second interface. The internal module is further configured to deliver a check signal from at least the first detection signal.

Abstract: An electromagnetic transponder includes an oscillatory circuit, a battery and a first rectifier bridge. Alternating current input terminals of the rectifier bridge are connected to the terminals of the oscillatory circuit, and at least two rectifier elements of the rectifier bridge are controllable on the basis of the voltage supplied by the battery.

Abstract: An NFC component includes a first interface that can be used in reader mode and is configured to be connected to an antenna via an impedance matching external circuit. A second interface can be used in card mode and in reader mode and is configured to be connected to the antenna and to the first interface via the impedance matching external circuit. An internal module includes a first detection circuit configured to deliver a first detection signal that represents the phase antenna matching quality when the impedance matching external circuit and the antenna are indeed connected between the first interface and the second interface. The internal module is further configured to deliver a check signal from at least the first detection signal.

Abstract: A method of determining, by a first device capable of transmitting a two-state signal over a single-wire connection to a second device, the binary state of data transmitted by the second device over said connection, the state being determined according to the slope of a rising edge of the two-state signal.

Abstract: A method of detection of the presence of a contactless communication element by a terminal emitting an electromagnetic field, in which an oscillating circuit of the terminal is excited at a frequency which is made variable between two values surrounding a nominal tuning frequency of the oscillating circuit; a signal representative of the load of the oscillating circuit being interpreted to detect that a reference voltage has not been exceeded, which indicates the presence of an element in the field. A presence-detection circuit and a corresponding terminal.