Samsung Electronics Co., Ltd.

Jongpil Cho

Seungwon Lee

Sanghyo Lee

Kyeongdo Kim

Youngjoo Lee

Junho Kim

Iljong Song

Byeongtaek Moon

Junesoo Kim

A smart card includes an antenna to transmit and to receive a radio frequency signal, a rectifier to rectify a signal received through the antenna to output a rectified voltage, a voltage regulator to operate in a first operation mode for stabilizing a level of the rectified voltage and a second operation mode for generating an internal voltage using the rectified voltage, a regulator converter to control the voltage regulator to operate the voltage regulator in one of the first operation and the second operation according to a mode selection signal, a clamp circuit to connect an output terminal of the rectifier to a ground according to the mode selection signal, a load modulator to vary a resistance of the antenna to perform a load modulation, and a regulator controller to generate the mode selection signal according to whether the load modulator is activated or deactivated.

Mode-changeable power supply circuit and smart card including the same

Disclosed is a near field communication device which includes an antenna, a transmission amplifier, a matching circuit connected between the antenna and the transmission amplifier, and a transmitter. The transmitter transmits a transmit clock to the matching circuit through the transmission amplifier, extracts an extraction clock from a waveform formed in the matching circuit, stores a phase difference between the transmit clock and the extraction clock, and controls transmission of an information signal through the antenna, the transmission amplifier, and the matching circuit based on the phase difference.

Near field communication device

A near field communication device includes an antenna, a matching circuit connected to the antenna, a clock extraction block that extracts a clock from a signal received by the antenna and outputs the extracted clock, a frequency compensation block that compensates for a frequency of the extracted clock and outputs a compensated clock, and a modulation and amplification block that performs modulation and amplification by using the compensated clock and outputs a transmit signal to the matching circuit. A first extracted clock has a first frequency that is extracted when the transmit signal is not output and a second extracted clock has a second frequency that is extracted when the transmit signal is output, the frequency compensation block compensates for the second frequency of the second extracted clock based on a difference between the first frequency of the first extracted clock and the second frequency of the second extracted clock.

Near field communication device and an operating method of the near field communication device

A radio-frequency (RF) communication device having a near field communication (NFC) function includes a first detection mode circuit configured to output an RF input signal received by an antenna as a first RF signal while the first detection mode circuit is enabled, and a second detection mode circuit configured to amplify the RF input signal and output the amplified RF input signal as a second RF signal while the second detection mode circuit is enabled. The first detection mode circuit is enabled during a first time period, and the second detection mode circuit is enabled during a second time period. The second time period is shorter than the first time period. The first and second detection mode circuits are enabled alternately and repeatedly.

Growing community of inventors

Hwaseong-si, South Korea

Jongpil Cho