Abstract: An operation of calibrating the object using a reference reader is performed, the calibration operation including an operation of placing the reference reader at various distances away from the object that correspond to various values of a parameter within the object that is representative of the intensity of the signal received by the object, and, for each distance, an operation of determining an internal phase-shift compensation in the object with respect to a nominal internal phase shift, making it possible to obtain a load modulation amplitude that is higher, in terms of absolute value, than a threshold, and an operation of storing a lookup table of the various values of the parameter and the corresponding internal phase-shift compensations.

Abstract: A first electronic device includes a first near-field communication antenna and a second near-field communication antenna. The first and second near-field communication antennas of the first electronic device are alternately activated. The first antenna is dedicated to supporting communication between the first electronic device and a second electronic device. The second antenna is dedicated to support charging of the second electronic device.

Abstract: An amplification circuit includes a first group of amplifiers including N first amplifiers, a second group of amplifiers including K second amplifiers, a first terminal, a second terminal, and a third terminal. Each of the N first amplifiers and each of the K second amplifiers includes an output. The second group of amplifiers is divided into a first subassembly of amplifiers and a second subassembly of amplifiers. The first subassembly includes M second amplifiers of the second group. The second subassembly includes K-M remaining second amplifiers of the second group. The first terminal is coupled to each output of the N first amplifiers and to a first radio frequency output terminal. The second terminal is coupled to each output of the M second amplifiers. The third terminal is coupled to each output of the K-M second remaining amplifiers and to a second radio frequency output terminal.

Abstract: A circuit for driving an antenna of near field communication (NFC) device, includes: a first variable resistor coupled to a first terminal of the antenna via a first capacitor; a second variable resistor coupled to a second terminal of the antenna via a second capacitor; and a control circuit configured to cause the first variable resistor and the second variable resistor to each have a selected one of a first resistance level, a second resistance level, and a third resistance level based on an operating phase of the circuit.

Abstract: A circuit for a communication device and a method for switching a communication device are disclosed. In an embodiment, a method includes activating at least one first antenna and at least one second antenna of a near-field communication (NFC) device for switching the NFC device between first field detection phases and second card detection phases.

Abstract: An operation of calibrating the object using a reference reader is performed, the calibration operation including an operation of placing the reference reader at various distances away from the object that correspond to various values of a parameter within the object that is representative of the intensity of the signal received by the object, and, for each distance, an operation of determining an internal phase-shift compensation in the object with respect to a nominal internal phase shift, making it possible to obtain a load modulation amplitude that is higher, in terms of absolute value, than a threshold, and an operation of storing a lookup table of the various values of the parameter and the corresponding internal phase-shift compensations.

Abstract: An electronic assembly includes a board and a system mounted to the board. The system includes an impedance matching circuit coupled to a contactless component. A detection circuit operates to carrying out a process for detecting on the board of potential faults in the system mounted to the board. The detection circuit includes a circuit incorporated into the contactless component itself and configured to carrying out a first part of the process for detecting. A processing circuit of the detection circuit performs a second part of the process for detecting based on results of the first part.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition. The value of the phase difference corresponding to the previously measured amplitude is stored.

Abstract: An amplification circuit includes a first group of amplifiers including N first amplifiers, a second group of amplifiers including K second amplifiers, a first terminal, a second terminal, and a third terminal. Each of the N first amplifiers and each of the K second amplifiers includes an output. The second group of amplifiers is divided into a first subassembly of amplifiers and a second subassembly of amplifiers. The first subassembly includes M second amplifiers of the second group. The second subassembly includes K-M remaining second amplifiers of the second group. The first terminal is coupled to each output of the N first amplifiers and to a first radio frequency output terminal. The second terminal is coupled to each output of the M second amplifiers. The third terminal is coupled to each output of the K-M second remaining amplifiers and to a second radio frequency output terminal.

Abstract: An amplification circuit includes a first group of amplifiers including N first amplifiers, a first terminal coupled to each output of the N first amplifiers, and a second group of amplifiers including N second amplifiers. Each of the N first amplifiers and each of the N second amplifiers includes an output. The second group of amplifiers is divided into a first subassembly of amplifiers and a second subassembly of amplifiers. The first subassembly includes M second amplifiers of the second group and the second subassembly includes N?M remaining second amplifiers of the second group. The amplification circuit further includes a second terminal and a third terminal. The second terminal is coupled to each output of the M second amplifiers and the third terminal is coupled to each output of the N?M second remaining amplifiers.

Abstract: In a general aspect, a method can include producing, by an inductive antenna circuit, a first periodic signal that is based on an alternating external magnetic field; producing, by an oscillator circuit, a second periodic signal that is based on the first periodic signal; and transmitting, in correspondence with a data-carrying modulation signal, a sequence of data bits. The transmitting can include sequentially and repetitively: applying, with the oscillator circuit operating in a free oscillation mode, the second periodic signal to the inductive antenna circuit; and inhibiting, with the oscillator circuit operating in a synchronous oscillation mode, application of the second periodic signal to the inductive antenna circuit. The synchronous oscillation mode of the oscillator circuit can cause the second periodic signal to be synchronized to the first periodic signal.

Abstract: A method of detection of the presence, by a first NFC device, of a second NFC device, during periodic field emission bursts, where detection thresholds are adjusted according to results obtained during one or a plurality of previous bursts.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition. The value of the phase difference corresponding to the previously measured amplitude is stored.

Abstract: An object is capable of contactless communication with a reader by active charge modulation. The object includes an antenna, an impedance matching circuit, a memory, and a controller connected to the antenna through the impedance matching circuit. The antenna, the an impedance matching circuit and the controller together form a resonant circuit having a resonant frequency. The controller is configured to cause the object to transmit, in the absence of a signal received from a reader, a signal at the resonant frequency, to determine a characteristic obtained from the signal uniquely transmitted by the object, and to perform an adjustment of a phase shift within the object based on the characteristic and an indication stored in the memory, the indication linking values of phase shifts with values of the characteristic.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition. The value of the phase difference corresponding to the previously measured amplitude is stored.

Abstract: An amplification circuit includes a first group of amplifiers including N first amplifiers, a first terminal coupled to each output of the N first amplifiers, and a second group of amplifiers including N second amplifiers. Each of the N first amplifiers and each of the N second amplifiers includes an output. The second group of amplifiers is divided into a first subassembly of amplifiers and a second subassembly of amplifiers. The first subassembly includes M second amplifiers of the second group and the second subassembly includes N?M remaining second amplifiers of the second group. The amplification circuit further includes a second terminal and a third terminal. The second terminal is coupled to each output of the M second amplifiers and the third terminal is coupled to each output of the N?M second remaining amplifiers.

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 method of detection of the presence, by a first NFC device, of a second NFC device, during periodic field emission bursts, where detection thresholds are adjusted according to results obtained during one or a plurality of previous bursts.

Abstract: A method for sending data by inductive coupling includes: extracting an antenna signal from an antenna circuit, extracting from the antenna signal a first periodic signal, producing a second periodic signal by way of a synchronous oscillator, placing the oscillator in a free oscillation mode and applying to the antenna circuit the second periodic signal, modifying the impedance of the antenna circuit, restoring the amplitude of the antenna signal, then resynchronizing the oscillator on the first periodic signal.

Abstract: A circuit for driving an antenna of near field communication (NFC) device, includes: a first variable resistor coupled to a first terminal of the antenna via a first capacitor; a second variable resistor coupled to a second terminal of the antenna via a second capacitor; and a control circuit configured to cause the first variable resistor and the second variable resistor to each have a selected one of a first resistance level, a second resistance level, and a third resistance level based on an operating phase of the circuit.