Em Microelectronic-marin Sa

Christian Lamothe

Goran Stojanovic

Thomas Coulot

Paul Muller

A dual communication frequency RFID circuit includes a logic unit for processing data signals received or transmitted at a first frequency by a first antenna or at a second frequency by a second antenna, and a unit for managing the state of a tamper loop linked to the integrated circuit by two connection terminals. The management unit includes a first low-pass filter linked to a first connection terminal, a second low-pass filter linked to a second connection terminal, a current source for supplying a current through the first low-pass filter, a switch linked at the output of the second low-pass filter, and a first inverter connected between the current source and the first low-pass filter for supplying an output signal for the state of the tamper loop to the logic unit.

Dual communication frequency RFID circuit equipped with a tamper-evident loop

A receiver unit for a radio frequency (RF) tag is provided, including a first input terminal and a second input terminal each being connected to an antenna; a communication stage configured to demodulate and/or to modulate an incoming signal in the communication stage; and a power stage including a voltage converter circuit being configured to supply power to the receiver unit, and a regulation circuit being configured to limit an output voltage of the voltage converter circuit, wherein the regulation circuit includes a regulator circuit being configured to determine a first current value and a second current value, the second current value being a current value provided in addition to the first current value, and, if the second current value exceeds a predetermined threshold value, to supply a control signal to a limiter circuit configured to limit an input voltage of the voltage converter circuit.

Receiver unit for an RF tag

A transponder circuit includes an antenna for receiving radio frequency signals and an extraction unit for extracting therefrom energy for the transponder circuit, a non volatile memory unit, a control logic unit that activates a received energy evaluation unit when a write operation is received. The evaluation unit is arranged directly at the antenna to provide the control logic unit with a signal representative of the status of energy available in the antenna indicating whether the available energy is greater than a minimum level for ensuring a proper write operation or not, wherein the control logic unit is arranged for performing, or not performing, the write operation. The evaluation unit includes a resistive divider including a set of resistors or a programmable current source and rectifier means on each connector of the antenna for simulating a write operation in the memory and energy recoverable by the power supply.

Device for checking energy received by an antenna for preventing data corruption during a write operation in a non volatile transponder memory

An integrated radiofrequency circuit () is provided that includes an antenna () for receiving radiofrequency signals, a rechargeable battery () and a battery charger () using the radiofrequency signals to charge said battery. The circuit is characterized in that the battery charger is integrated in the same substrate as the integrated radiofrequency circuit and in that the battery charger includes a calibrating mechanism, a current source calibrated by the calibrating mechanism and delivering a charge current of constant maximum intensity drawn from the received radiofrequency signals, and a comparator between a reference quantity representative of the end of battery charge level and a variable quantity representative of the battery charge level supplying at output a control signal (batchend) for charging or not charging the battery.

Battery charger operating 'all or nothing' with a protective power supply circuit for monolithic integrated circuits using the antenna energy

Electronic device for monitoring the temperature of a medium ensures that the temperature has not reached pre-established index limit values. The device includes contacts for closing an electric charge flow circuit when the temperature reaches an index limit value, an electric charge storage component connected to the charge flow circuit when the contacts close, the charges remain stored as long as the temperature does not reach one of its index limit values, and is able to flow through the charge flow circuit when the circuit is closed by the contacts, the charge storage not returning to the charge state which they had before the charge flow circuit closed if the latter opens again, and a provision for reading enabling the charge state to be determined.

Growing community of inventors

Travers, Switzerland

Christian Lamothe