Abstract: An NFC (near field communication) device can include a resonance unit and an NFC chip. The resonance unit may communicate with an external device through an electromagnetic wave. The NFC chip can provide output data to the resonance unit, receive input data from the resonance unit, and can reduce a Q factor (quality factor) of the resonance unit when a signal receive operation is performed in a card mode, and can maintain the Q factor of the resonance unit in a reader mode and when a signal transmit operation is performed in the card mode.

Abstract: An NFC (near field communication) device can include a resonance unit and an NFC chip. The resonance unit may communicate with an external device through an electromagnetic wave. The NFC chip can provide output data to the resonance unit, receive input data from the resonance unit, and can reduce a Q factor (quality factor) of the resonance unit when a signal receive operation is performed in a card mode, and can maintain the Q factor of the resonance unit in a reader mode and when a signal transmit operation is performed in the card mode.

Abstract: An NFC (near field communication) device can include a resonance unit and an NFC chip. The resonance unit may communicate with an external device through an electromagnetic wave. The NFC chip can provide output data to the resonance unit, receive input data from the resonance unit, and can reduce a Q factor (quality factor) of the resonance unit when a signal receive operation is performed in a card mode, and can maintain the Q factor of the resonance unit in a reader mode and when a signal transmit operation is performed in the card mode.

Abstract: A method of operating a near field communication (NFC) device includes receiving, by the NFC device, a first signal from an NFC reader, transmitting, by the NFC device, a response to the first signal to the NFC reader and changing selectively, by the NFC device, a radio frequency (RF) configuration parameter associated with signal transmission operation during a signal transmission interval, based on determining whether the NFC reader recognizes the response.

Abstract: An NFC (near field communication) device can include a resonance unit and an NFC chip. The resonance unit may communicate with an external device through an electromagnetic wave. The NFC chip can provide output data to the resonance unit, receive input data from the resonance unit, and can reduce a Q factor (quality factor) of the resonance unit when a signal receive operation is performed in a card mode, and can maintain the Q factor of the resonance unit in a reader mode and when a signal transmit operation is performed in the card mode.

Abstract: A method of operating a near field communication (NFC) device includes receiving, by the NFC device, a first signal from an NFC reader, transmitting, by the NFC device, a response to the first signal to the NFC reader and changing selectively, by the NFC device, a radio frequency (RF) configuration parameter associated with signal transmission operation during a signal transmission interval, based on determining whether the NFC reader recognizes the response.

Abstract: A demodulator for a near field communication (NFC) includes a first rectifier, a shifting rectifier, a field monitor and an edge detector. The first rectifier receives an antenna voltage through a first power terminal and a second power terminal, rectifies the antenna voltage and provides a first rectified signal to a first node. The shifting rectifier is enabled in response to an enable signal, receives the antenna voltage through the first power terminal and the second power terminal, increases a direct current (DC) level of the antenna voltage, rectifies the increased DC-level antenna voltage and provides a shifted rectified signal to the first node. The field monitor receives the antenna voltage through the first power terminal and the second power terminal, monitors a magnitude of the antenna voltage and generates the enable signal which is activated when the magnitude is smaller than a reference value.

Abstract: A semiconductor device including a PLL providing candidate clocks of different phases in response to a first clock received from a reader via an antenna, a phase difference detector detecting a phase difference between the first clock and a clock from the candidate clocks, a phase difference controller that selects another clock from the candidate clocks, and a driver that provides transmission data synchronously with the another clock to the reader.

Abstract: A Near Field Communication (NFC) device, system, and method are disclosed. The NFC device includes a resonance unit configured to emit a first electromagnetic wave to communicate with an external NFC card in a reader mode, and an NFC chip configured to measure an antenna voltage generated by the resonance unit while the resonance unit emits the first electromagnetic wave, and configured to control the resonance unit to stop emitting the first electromagnetic wave when a magnitude of the antenna voltage oscillates.

Abstract: An NFC (near field communication) device can include a resonance unit and an NFC chip. The resonance unit may communicate with an external device through an electromagnetic wave. The NFC chip can provide output data to the resonance unit, receive input data from the resonance unit, and can reduce a Q factor (quality factor) of the resonance unit when a signal receive operation is performed in a card mode, and can maintain the Q factor of the resonance unit in a reader mode and when a signal transmit operation is performed in the card mode.

Abstract: A method of operating a near field communication (NFC) device includes receiving, by the NFC device, a first signal from an NFC reader, transmitting, by the NFC device, a response to the first signal to the NFC reader and changing selectively, by the NFC device, a radio frequency (RF) configuration parameter associated with signal transmission operation during a signal transmission interval, based on determining whether the NFC reader recognizes the response.

Abstract: A demodulator for a near field communication (NFC) includes a first rectifier, a shifting rectifier, a field monitor and an edge detector. The first rectifier receives an antenna voltage through a first power terminal and a second power terminal, rectifies the antenna voltage and provides a first rectified signal to a first node. The shifting rectifier is enabled in response to an enable signal, receives the antenna voltage through the first power terminal and the second power terminal, increases a direct current (DC) level of the antenna voltage, rectifies the increased DC-level antenna voltage and provides a shifted rectified signal to the first node. The field monitor receives the antenna voltage through the first power terminal and the second power terminal, monitors a magnitude of the antenna voltage and generates the enable signal which is activated when the magnitude is smaller than a reference value.

Abstract: A demodulator for near field communication may include: a scale down circuit configured to receive first and second modulated signals from first and second power electrodes, and configured to provide a scale down signal to a first node by scaling down magnitudes of the first and second modulated signals; a current source coupled between the first node and a ground voltage, and configured to generate a constant current flowing from the first node to the ground voltage; a charge store circuit coupled between the first node and ground voltage, and configured to perform charge and discharge operations alternately, based on the scale down signal and constant current, to output an envelope signal, which corresponds to an envelope of the scale down signal; and/or an edge detector configured to generate input data, which correspond to the first and second modulated signals, based on a transition of the envelope signal.

Abstract: A near field communication (NFC) terminal includes a first signal generator configured to generate a first received signal using a radio frequency (RF) signal received through an antenna, and generate a reduced first received signal by reducing a size of the first received signal when the size of the first received signal is equal to or greater than a predetermined RF value. The NFC terminal further includes a second signal generator configured to generate a second received signal using the RF signal. The NFC terminal further includes an operation unit configured to generate an operation signal by performing an operation on the reduced first received signal and the second received signal, and transmit the operation signal to a demodulator.

Abstract: A voltage generator of a contactless integrated circuit (IC) card includes a regulator configured to generate a first internal voltage based on an input voltage and a first reference voltage, the input voltage being received through an antenna of the contactless IC card. The voltage generator includes an internal voltage generator configured to generate a second internal voltage, the second internal voltage being used to operate an internal circuit of the contactless IC card. The voltage generator includes a reference voltage generator configured to generate a second reference voltage based on the first internal voltage, the second reference voltage being generated without regard to a fluctuation component of the first internal voltage. The voltage generator includes a switching unit configured to provide one of the first and second internal voltages as the first reference voltage in response to first and second switching control signals.

Abstract: A demodulator for near field communication may include: a scale down circuit configured to receive first and second modulated signals from first and second power electrodes, and configured to provide a scale down signal to a first node by scaling down magnitudes of the first and second modulated signals; a current source coupled between the first node and a ground voltage, and configured to generate a constant current flowing from the first node to the ground voltage; a charge store circuit coupled between the first node and ground voltage, and configured to perform charge and discharge operations alternately, based on the scale down signal and constant current, to output an envelope signal, which corresponds to an envelope of the scale down signal; and/or an edge detector configured to generate input data, which correspond to the first and second modulated signals, based on a transition of the envelope signal.

Abstract: A semiconductor device including a PLL providing candidate clocks of different phases in response to a first clock received from a reader via an antenna, a phase difference detector detecting a phase difference between the first clock and a clock from the candidate clocks, a phase difference controller that selects another clock from the candidate clocks, and a driver that provides transmission data synchronously with the another clock to the reader.

Abstract: A Near Field Communication (NFC) device, system, and method are provided. The NFC device includes a resonance unit configured to emit a first electromagnetic wave to communicate with an external NFC card in a reader mode, and an NFC chip configured to measure an antenna voltage generated by the resonance unit while the resonance unit emits the first electromagnetic wave, and configured to control the resonance unit to stop emitting the first electromagnetic wave when a magnitude of the antenna voltage oscillates.

Abstract: A near field communication (NFC) terminal includes a first signal generator configured to generate a first received signal using a radio frequency (RF) signal received through an antenna, and generate a reduced first received signal by reducing a size of the first received signal when the size of the first received signal is equal to or greater than a predetermined RF value. The NFC terminal further includes a second signal generator configured to generate a second received signal using the RF signal. The NFC terminal further includes an operation unit configured to generate an operation signal by performing an operation on the reduced first received signal and the second received signal, and transmit the operation signal to a demodulator.

Abstract: An internal voltage generating circuit includes a first voltage application unit, a second voltage application unit, a first regulator, a second regulator, and a controller. The first and second voltage application units respectively provide a first voltage and a second voltage. The controller generates a bulk voltage, a first control signal, and a second control signal from the first and second voltages. The first regulator is enabled or disabled according to the first control signal and generates and outputs the first internal voltage based on the bulk voltage, the first voltage, and a first reference voltage. The second regulator is enabled or disabled according to the second control signal and generates and outputs the second internal voltage based on the bulk voltage, the second voltage, and a second reference voltage.