Nxp B.v.

Ivan Jesus Rebollo Pimentel

Thomas Pichler

Gerhard Martin Landauer

Slawomir Rafal Malinowski

Christian Weidinger

Egas Carvalho Henes Neto

Franz Amtmann

Maurits Mario Nicolaas Storms

Ronald Van Langevelde

Stefan Maier

Werner Zettler

Heinz Umfahrer

Harcharan Singh Madaan

A voltage limiter for a radio-frequency identification (RFID) integrated circuit (IC) for an RFID tag and a method for operating a voltage limiter is disclosed. The RFID IC includes a radio-frequency (RF) rectifier. The voltage limiter comprises: a current sink device coupled between an output of the RF rectifier and ground; a reference generator having an output for providing a reference voltage (Vlim) for controlling a current through the current sink device to limit a voltage (Vrec) at the output of the RF rectifier to values below a predefined voltage level; and feedback circuitry arranged to provide a feedback current to the reference generator to vary the reference voltage (Vlim), the feedback current being dependent on the current through the current sink device.

Voltage limiter for an RFID tag

It is described an RF communication device comprising: The antenna pad and the non-antenna pad are arranged to be short-circuited with each other, and the non-antenna pad is electrically connected via a connection line to the further functionality within the RF communication device. Further, a method of manufacturing an RF communication device is described.

RF communication device without temporary connection line, and manufacturing method

A voltage regulator is provided. The voltage regulator includes a shunt transistor and a feedback circuit. The shunt transistor has a first current electrode coupled to a first voltage source terminal, a second current electrode coupled to a second voltage source terminal, a control electrode coupled to receive a reference voltage, and a body electrode. The feedback circuit has an input terminal coupled to the body electrode of the shunt transistor, and an output terminal coupled to the control electrode of the shunt transistor. The voltage regulator is suitable for use in a passive RFID device to protect the device from over-voltage damage. In another embodiment, a method for regulating a voltage is provided.

Voltage regulator circuit and method for regulating a voltage

In accordance with a first aspect of the present disclosure, a radio frequency identification (RFID) transponder is provided, comprising: a receiver configured to receive a command from an external RFID reader, wherein the command is a first command transmitted by the RFID reader during a communication session and wherein said command comprises a at least one parameter indicative of one or more modifiable settings of the RFID transponder; and a controller configured to modify the settings of the RFID transponder in accordance with a value of said parameter. In accordance with a second aspect of the present disclosure, a corresponding method of operating a radio frequency identification (RFID) transponder is conceived.

RFID transponder having modifiable settings

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive a high frequency signal, a capacitor bank coupled with the antenna, a charge pump coupled with the antenna configured to convert the high frequency signal to a direct current (DC) signal, an envelope detector to measure peak voltage of the high frequency signal and a detector to compare an output of the charge pump and an output of the envelope detector. The RFID tag also includes an impedance tuning circuit coupled with the charge pump and the envelope detector configured change a capacitance of the capacitor bank based on an output of the detector and the envelope detector.

RFID tag with impedance tuning,and method of impedance tuning of an RRID tag

A voltage limiter incorporated in a radio frequency identification (RFID) integrated circuit (IC) for a RFID tag is disclosed. The RFID IC includes a radio frequency (RF) rectifier and a clock generator. The RF rectifier is configured to convert an AC signal received from an antenna incorporated in the RFID tag to a DC signal. The voltage limiter includes a current sink device coupled between output of the RF rectifier and ground and a charge pump to control conduction of current through the current sink device to limit output voltage of the RF rectifier to a predefined voltage level.

Voltage limiter

A ground switch is disclosed. The ground switch includes an antenna port, a pair of switching devices coupled with the antenna port and a charge pump coupled with the pair of devices and configured to turn on/off the pair of devices based on an AC input signal received through the antenna port and a DC offset voltage added to the AC input signal. The ground switch further includes a clamping circuit to clamp an output of the charge pump. The ground switch is configured to provide a stable ground to components of devices such that a radio frequency identification (RFID) device.

Ground switch

There is described a rectifier circuit for providing and limiting a supply voltage to an RFID tag, the circuit including a pair of antenna input terminals configured to receive an input signal from an RFID tag antenna. A plurality of charge pump stages are coupled in cascade in such a way that an input terminal of a first charge pump stage in the cascade is connected to ground and an input terminal of each subsequent charge pump stage in the cascade is coupled to an output terminal of the preceding charge pump stage in the cascade. A control logic is configured to select the output terminal of one charge pump stage among the plurality of charge pump stages to provide the supply voltage. Furthermore, an RFID tag and a method of providing and limiting a supply voltage to an RFID tag are described.

Rectifier circuits and corresponding methods for RFID devices

In accordance with a first aspect of the present disclosure, a radio frequency identification (RFID) transponder is provided, comprising a charge pump and at least one functional component, wherein: the charge pump is configured to convert an input voltage into an output voltage and to supply the output voltage to the functional component; the functional component is configured to perform a function of the RFID transponder using the output voltage of the charge pump; wherein the charge pump comprises a diode or switch transistor and at least one capacitor coupled to said diode or switch transistor, and wherein the capacitor is configured to compensate for a change of an impedance of said diode or switch transistor. In accordance with a second aspect of the present disclosure, a corresponding method of operating an RFID transponder is conceived.

RFID transponder and method of operating an RFID transponder

A radio frequency identification (RFID) transponder includes a current control module for controlling a current consumption of a memory based on an amount of available power, and a control logic for controlling a memory operation in response to the control of the current consumption by the current control module. The RFID transponder further includes a power detector that is configured to continuously monitor and detect the amount of available power and output a power-dependent control signal. The power-dependent control signal is used by the RFID transponder to control the current consumption of the memory in dependence on the available power.

Agile time-continuous memory operation for a radio frequency identification transponder

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna port to receive an input AC signal and a hybrid limiter including a clamping device configured to limit a voltage of the input AC signal to a preconfigured limit. The hybrid limiter is configured to provide a stable ground reference for the clamping device.

RFID tag limiter

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive an input AC signal and a tuning system coupled with the antenna to optimize signal strength of the input AC signal. The tuning system includes a charge pump rectifier. A diode rectifier is included and is coupled with the antenna to receive the input AC signal after the tuning system optimizes the signal strength by tuning input impedance of the antenna.

Dual system RFID tag

A charge pump for a Radio Frequency Identification (RFID) tag is disclosed. The charge pump includes an antenna port to receive an input AC signal, an input port to receive an input signal, and a main transistor having a gate, a source and a drain. A threshold voltage cancellation circuit is included and is coupled between one terminal of the antenna port and the input port, wherein an output of the threshold voltage cancellation circuit is configured to drive the gate of the main transistor. The threshold voltage cancellation circuit is configured to reduce the threshold voltage of the main transistor when the voltage of the input signal is below a predefined voltage level and to remove threshold voltage cancellation when the voltage of the input signal is above the predefined voltage levels.

Self limiting charge pump

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna port to receive an input AC signal and a self-tuning circuit coupled with the antenna port to optimize signal strength of the input AC signal during a self-tuning phase. The RFID tag further includes an AC limiter configured to limit the voltage of the input AC signal to a preconfigured limit and a limiter controller configured to disable the AC limiter during the self-tuning phase and re-enable the AC limiter after the self-tuning phase. The self-tuning phase occurs prior to the data communication period in which the data stored in the RFID tag is transmitted back to a reader.

RFID tag self tuning

In accordance with a first aspect of the present disclosure, a radio frequency identification (RFID) transponder is provided, comprising: at least one functional component configured to perform a function of the RFID transponder; a charge pump configured to supply an output voltage to said functional component, wherein said charge pump comprises a plurality of charge pump stages; a charge pump controller configured to control a number of charge pump stages which contribute to the output voltage. In accordance with a second aspect of the present disclosure, a corresponding method of operating an RFID transponder is conceived.

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Graz, Austria

Ivan Jesus Rebollo Pimentel