Abstract: A near field communications (NFC) device is disclosed that detects an envelope of a radio frequency (RF) signal. The NFC device includes a peak detector that determines the envelope of the RF signal. The peak detector compares a first differential signal voltage to a second differential signal voltage. The peak detector delays a rising edge of a first differential signal and provides the first differential signal voltage to the peak detector output when the first differential signal voltage is greater than the second differential signal voltage. The peak detector delays a falling edge of a second differential signal and provides the second differential signal voltage to the peak detector output when the second differential signal voltage is greater than the first differential signal voltage.

Abstract: A near field communications (NFC) device is disclosed that detects an envelope of a radio frequency (RF) signal. The NFC device includes a peak detector that determines the envelope of the RF signal. The peak detector compares a first differential signal voltage to a second differential signal voltage. The peak detector delays a rising edge of a first differential signal and provides the first differential signal voltage to the peak detector output when the first differential signal voltage is greater than the second differential signal voltage. The peak detector delays a falling edge of a second differential signal and provides the second differential signal voltage to the peak detector output when the second differential signal voltage is greater than the first differential signal voltage.

Abstract: A near field communications (NFC) device is disclosed that detects an envelope of a radio frequency (RF) signal. The NFC device includes a peak detector that determines the envelope of the RF signal. The peak detector compares a first differential signal voltage to a second differential signal voltage. The peak detector delays a rising edge of a first differential signal and provides the first differential signal voltage to the peak detector output when the first differential signal voltage is greater than the second differential signal voltage. The peak detector delays a falling edge of a second differential signal and provides the second differential signal voltage to the peak detector output when the second differential signal voltage is greater than the first differential signal voltage.

Abstract: An apparatus and method is disclosed to optimize power consumption in a NFC environment. A first NFC capable device provides a polling command to a second NFC capable device. The second NFC capable device provides a response to the polling command. The first NFC capable device provides a read command to the second NFC capable device. The second NFC capable device provides a response to the read command that indicates an overvoltage condition is present. The first NFC capable device adjusts a power level that is to be used to transmit further commands when the overvoltage condition is present.

Abstract: A near field communications (NFC) device is disclosed that interacts with other NFC devices to exchange information and/or the data. Another NFC device inductively couples a received communications signal onto an antenna circuit of the NFC device to provide a recovered communications signal. An overvoltage protection module regulates a power level of the recovered communication signal by detuning the antenna circuit when the power level of the recovered communication signal may cause damage the NFC device. Active components of the overvoltage protection module, such as voltage controlled impedances, operate in their linear mode of operation to reduce unwanted emissions during this regulation process.

Abstract: An NFC-enabled device includes a load modulation communication section providing two or more selectable changes in the load impedance across the antenna terminals. At least one of the two or more selectable changes is dependent on both the transmit data arid the concurrently detected strength of a tag reader field coupled to the NFC antenna.

Abstract: An apparatus and method is disclosed to optimize power consumption in a NFC environment. A first NFC capable device provides a polling command to a second NFC capable device. The second NFC capable device provides a response to the polling command. The first NFC capable device provides a read command to the second NFC capable device. The second NFC capable device provides a response to the read command that indicates an overvoltage condition is present. The first NFC capable device adjusts a power level that is to be used to transmit further commands when the overvoltage condition is present.

Abstract: A near field communications (NFC) device is disclosed that detects an envelope of a radio frequency (RF) signal. The NFC device includes a peak detector that determines the envelope of the RF signal. The peak detector compares a first differential signal voltage to a second differential signal voltage. The peak detector delays a rising edge of a first differential signal and provides the first differential signal voltage to the peak detector output when the first differential signal voltage is greater than the second differential signal voltage. The peak detector delays a falling edge of a second differential signal and provides the second differential signal voltage to the peak detector output when the second differential signal voltage is greater than the first differential signal voltage.

Abstract: A near field communications (NFC) device is disclosed that interacts with other NFC devices to exchange information and/or the data. Another NFC device inductively couples a received communications signal onto an antenna circuit of the NFC device to provide a recovered communications signal. An overvoltage protection module regulates a power level of the recovered communication signal by detuning the antenna circuit when the power level of the recovered communication signal may cause damage the NFC device. Active components of the overvoltage protection module, such as voltage controlled impedances, operate in their linear mode of operation to reduce unwanted emissions during this regulation process.