Abstract:
A near-field communication (NFC) circuit includes a transmitter that generates a transmission signal based on a reference clock signal and transmits the transmission signal through an antenna; a clock recovery circuit that receives a detection signal through the antenna responsive to the transmission signal and recovers a recovered clock signal from the detection signal; a phase detector that detects a phase change of the recovered clock signal; and a controller that determines, based on the phase change of the recovered clock signal, whether an NFC tag external to the NFC circuit is located within a communication range of the NFC circuit.
Abstract:
A semiconductor device includes a substrate, a memory structure and a capacitor structure including at least one array of capacitors. The memory structure is disposed in a first region of the device. The capacitor structure is disposed in a second region of the device. The capacitor structure may include a first capacitor array, a second capacitor array, a third capacitor array and a first landing pad. The first landing pad is disposed between the substrate and lower electrodes of capacitors of the first and second capacitor arrays, and contacts the lower electrodes so as to electrically connect the first capacitor array and the second capacitor array. Upper electrodes of capacitors of the second and third capacitor arrays are integral such that the second capacitor array and the third capacitor array are electrically connected to each other.
Abstract:
A reception circuit of an NFC card, includes, an input circuit, a reference voltage generator, a comparison circuit and a reference voltage controller. The input circuit receives a wireless signal including pauses and generates an envelope voltage signal. The reference voltage generator generates a detection reference voltage and a selection reference voltage based on the envelope voltage signal and a voltage selection signal. The selection reference voltage varies depending on a minimum voltage level of the pauses. The comparison circuit generates a pause detection signal and a synchronization signal by comparing the envelope voltage signal with the detection reference voltage the selection reference voltage, respectively. The reference voltage controller adjusts a control value of the voltage selection signal based on the pause detection signal and the synchronization signal such that the selection reference voltage is changed depending on the control value of the voltage selection signal.
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.