Abstract: An integrated circuit includes an internal resistance (RINT) and a compensation circuit coupled to adjust a slice level specified by a slice signal to a compensated slice level according to a difference between the internal resistance (RINT) and a known resistance (REXT). A reference voltage is coupled to the internal resistance to generate an internal current and is coupled to the known resistance to generate a known current. The compensated slice level is determined according to the internal current and the known current. The compensated slice level may be generated using an analog to digital converter coupled to a digital to analog converter that scale original slice signal based on the internal and known currents.

Abstract: In accordance with one aspect of the present invention, there is provided a method of calibrating an oscillator within a radio-frequency identification (RFID) circuit for use in an RFID tag. The oscillator has an oscillation frequency. A calibration value is stored within a non-volatile memory associated with the RFID circuit. The oscillator is calibrated in accordance with the calibration value. The storing of the calibration value includes recovering a reference frequency from a test signal supplied to the RFID circuit, calculating the calibration value to correspond to a difference between the recovered reference frequency and the oscillator frequency, and writing the calibration value to the non-volatile memory.

Abstract: According to one aspect of the present invention, there is provided a method to backscatter modulate a first radio-frequency (RF) signal from a radio-frequency identification (RFID) tag. An oscillator calibration value is retrieved from a non-volatile memory associated with the RFID tag. An oscillation frequency signal is generated within the RFID tag, the generating of the oscillation signal being performed utilizing the oscillator calibration value. A command signal is generated within the RFID tag, the command signal being based on command data received at the RFID tag in a second radio-frequency signal from an RFID reader. The first radio-frequency signal is backscatter modulated in accordance with both the oscillation frequency signal and the command signal.

Abstract: Two floating gate devices are arranged in a redundant configuration in a non-volatile memory (NVM) of a Radio Frequency Identification (RFID) tag such that stress induced leakage current (SILC) or other failures do not result in a complete loss of memory storage. The redundant NVM may be arranged as a series configuration, a parallel configuration, a single-ended device, a differential device, a simple logic circuit function, and/or a complex logic circuit function.

Abstract: An RFID tag has a fuse that is adapted to store configuration data in a way that survives loss of power. The fuse can be one time programmable or many times programmable, and be implemented with a non-volatile memory. The configuration data becomes available to an operational component of the tag, such as at power up, controlling its performance.

Abstract: Methods and apparatus may operate to use multiple oscillators to generate a demodulator clock signal and a modulator clock signal within a radio-frequency identification (RFID) circuit. The demodulator clock signal may be generated from a radio-frequency signal received at the RFID circuit. A modulator clock signal may be generated using a calibration value stored in a non-volatile memory.

Abstract: A loss-of-signal (LOS) condition is detected by sampling input data for a predetermined time period, comparing a magnitude of the sampled input data to a threshold signal strength level, and asserting a LOS indication if the number of samples that have signal strength less than the threshold signal strength level is less than a predetermined value.

Abstract: A random number generator for an RFID tag is described. In one such embodiment the random number generator includes a noise-controlled component comprising a noise source circuit that outputs a noise-based signal operable to generate random numbers from the noise-based signal. The noise-based signal is variable due to noise.

Abstract: A ring oscillator has multiple stages that are independently adjustable. The delay is controlled using digital signals supplied to the stages. Each stage may receive two digital signals to control the delay with outputs of the particular stage controlling which of the two digital signals is used to control the delay through the stage at any particular time. The stages of the ring oscillator may be biased towards either supplying a faster or slower output signal. Each stage of the ring oscillator includes a tail node having a gate of a first transistor coupled to a digital control signal that adjusts a delay of the ring oscillator stage by turning on or off the transistor and a second transistor having a gate input coupled to a first or second voltage.

Abstract: A method of calibrating an oscillator within a Radio-Frequency Identification (RFID) tag includes storing a plurality of calibration values within a memory structure. Each of the calibration values corresponds to a respective oscillation frequency of the oscillator. A selected calibration value is selected from the plurality of calibration values stored, according to a first selection criterion. The oscillator is then calibrated in accordance with the selected calibration value.

Abstract: According to one aspect of the present invention, there is provided a method of calibrating an oscillator within a radio-frequency identification (RFID) circuit for use in an RFID tag. A plurality of calibration values is stored within a memory structure associated with the RFID circuit. Each of the calibration values corresponds to a respective oscillation frequency of the oscillator. A selected calibration value is selected from the plurality of calibration values stored within the memory structure, according to a first selection criterion. The oscillator is then calibrated in accordance with the selected calibration value.

Abstract: Two floating gate devices are arranged in a redundant configuration in a non-volatile memory (NVM) such that stress induced leakage current (SILC) or other failures do not result in a complete loss of memory storage. The redundant NVM may be arranged as a series configuration, a parallel configuration, a single-ended device, a differential device, a simple logic circuit function, a complex logic circuit function, and/or as part of an RFID tag system.

Abstract: Apparatus and method for generating random numbers in an RFID tag circuit. The RFID tag circuit includes a random number generator (RNG) operable to output a random number based on a seed value and further includes a non-volatile memory (NVM) register operable to store an updatable seed value that is to be used by the RNG. A tag controller included in the RFID tag is operable to select a first one, and then a second one of a plurality of values that is to become the stored seed value.

Abstract: An RFID tag has a fuse that is adapted to store configuration data in a way that survives loss of power. The fuse can be one time programmable or many times programmable, and be implemented with a non-volatile memory. The configuration data becomes available to an operational component of the tag, such as at power up, controlling its performance.

Abstract: An RFID tag has a Non Volatile Memory (NVM) array that can store data in a way that survives loss of power. The data is configuration data that controls the operation of an operational component of the tag. A performance of the operational component is thus adjusted according to the configuration data, and the adjustment is retained.

Abstract: In accordance with one aspect of the present invention, there is provided a method of calibrating an oscillator within a radio-frequency identification (RFID) circuit for use in an RFID tag. The oscillator has an oscillation frequency. A calibration value is stored within a non-volatile memory associated with the RFID circuit. The oscillator is calibrated in accordance with the calibration value. The storing of the calibration value includes recovering a reference frequency from a test signal supplied to the RFID circuit, calculating the calibration value to correspond to a difference between the recovered reference frequency and the oscillator frequency, and writing the calibration value to the non-volatile memory.

Abstract: According to one aspect of the present invention, there is provided a method of calibrating an oscillator within a radio-frequency identification (RFID) circuit for use in an RFID tag. A plurality of calibration values is stored within a memory structure associated with the RFID circuit. Each of the calibration values corresponds to a respective oscillation frequency of the oscillator. A selected calibration value is selected from the plurality of calibration values stored within the memory structure, according to a first selection criterion. The oscillator is then calibrated in accordance with the selected calibration value.

Abstract: According to one aspect of the present invention, there is provided a method to generate a demodulator clock signal and a modulator clock signal within an RFID circuit for use within an RFID tag. The demodulator clock signal is generated from a radio-frequency signal received at the RFID tag. A modulator clock signal is generated utilizing a first calibration value, stored within a non-volatile memory associated with the RFID tag.

Abstract: According to one aspect of the present invention, there is provided a method to backscatter modulate a first radio-frequency (RF) signal from a radio-frequency identification (RFID) tag. An oscillator calibration value is retrieved from a non-volatile memory associated with the RFID tag. An oscillation frequency signal is generated within the RFID tag, the generating of the oscillation signal being performed utilizing the oscillator calibration value. A command signal is generated within the RFID tag, the command signal being based on command data received at the RFID tag in a second radio-frequency signal from an RFID reader. The first radio-frequency signal is backscatter modulated in accordance with both the oscillation frequency signal and the command signal.

Abstract: According to one aspect of the present invention, there is provided a method of calibrating an oscillator within a radio-frequency identification (RFID) circuit for use in an RFID tag. A first calibration value is stored within a non-volatile memory associated with the RFID circuit. The oscillator is calibrated in accordance with the first calibration value. The storing of the first calibration value is performed responsive to receiving a calibration command and an associated update value at the RFID circuit.