Abstract: In certain aspects, an analog-to-digital converter (ADC) includes a comparator having a first input, a second input, and an output. The ADC also includes a digital-to-analog converter (DAC) coupled to the first input of the comparator, a switching circuit, a first capacitor coupled between the first input of the comparator and the switching circuit, a second capacitor coupled between the first input of the comparator and the switching circuit, and an amplifying circuit having an input and an output, wherein the input of the amplifying circuit is coupled to the switching circuit. The ADC further includes a first switch coupled between the output of the amplifying circuit and the DAC, and a successive approximation register (SAR) having an input and an output, wherein the input of the SAR is coupled to the output of the comparator, and the output of the SAR is coupled to the DAC.

Abstract: In certain aspects, an analog-to-digital converter includes a first capacitive digital-to-analog converter (DAC), a second capacitive DAC, and a comparator including a first input, a second input, and an output. The analog-to-digital converter also includes a switch circuit including a first input coupled to the first capacitive DAC, a second input coupled to the second capacitive DAC, a first output coupled to the first input of the comparator, and a second output coupled to the second input of the comparator. The analog-to-digital converter further includes a first switch coupled between the output of the comparator and the first input of the comparator, and a successive approximation register (SAR) coupled to the output of the comparator, the first capacitive DAC, and the second capacitive DAC.

Abstract: The present application relates to a near field communication (NFC) device which has an antenna for receiving NFC signals. The NFC device includes a protection system for protecting a transmit/receive system, and other systems, of the NFC device from potentially damaging voltages that may develop at an output of the antenna if the device enters a strong magnetic field. The protection system includes current control devices that are operative to source or sink current depending upon the polarity of a signal at an output of the antenna, to generate a voltage which at least partially negates a positive or negative voltage at the output of the antenna, thereby reducing the peak voltage at the antenna output.

Abstract: The present application relates to a near field communication (NFC) device which has an antenna for receiving NFC signals. The NFC device includes a protection system for protecting a transmit/receive system, and other systems, of the NFC device from potentially damaging voltages that may develop at an output of the antenna if the device enters a strong magnetic field. The protection system includes current control devices that are operative to source or sink current depending upon the polarity of a signal at an output of the antenna, to generate a voltage which at least partially negates a positive or negative voltage at the output of the antenna, thereby reducing the peak voltage at the antenna output.

Abstract: A receiver including: an antenna for receiving signals in a plurality of frequency ranges; a plurality of amplifiers, each of the plurality of amplifiers being configured to amplify signals in one of the plurality of frequency ranges; a plurality of receive paths, each of the plurality of receive paths connecting an output of the antenna to an input of one of the plurality of amplifiers, wherein each of the plurality of receive paths includes a power detector for monitoring signal power in the receive path and a switch which can be operated to activate or deactivate the receive path, wherein the switch of each receive path is operable to deactivate the receive path if an overload condition is detected by the power detector of that receive path.

Abstract: The present application relates to a near field communications (NFC) receiver in which a received NFC signal comprising a carrier signal onto which a data signal is modulated is digitised and downconverted, and the digitised and downconverted received signal is filtered to recover a digitised and downconverted version of the carrier signal of the NFC signal. This digitised and downconverted version of the carrier signal is converted into an analogue signal which is then upconverted to generate an estimate of the carrier signal, and this estimate is combined with the received NFC signal to suppress or negate, at least partially, the carrier of the received signal.

Abstract: The present application relates to a near field communications (NFC) receiver in which a received NFC signal comprising a carrier signal onto which a data signal is modulated is digitised and downconverted, and the digitised and downconverted received signal is filtered to recover a digitised and downconverted version of the carrier signal of the NFC signal. This digitised and downconverted version of the carrier signal is converted into an analogue signal which is then upconverted to generate an estimate of the carrier signal, and this estimate is combined with the received NFC signal to suppress or negate, at least partially, the carrier of the received signal.

Abstract: A receiver including: an antenna for receiving signals in a plurality of frequency ranges; a plurality of amplifiers, each of the plurality of amplifiers being configured to amplify signals in one of the plurality of frequency ranges; a plurality of receive paths, each of the plurality of receive paths connecting an output of the antenna to an input of one of the plurality of amplifiers, wherein each of the plurality of receive paths includes a power detector for monitoring signal power in the receive path and a switch which can be operated to activate or deactivate the receive path, wherein the switch of each receive path is operable to deactivate the receive path if an overload condition is detected by the power detector of that receive path.