Samsung Electronics Co., Ltd.

Ju Ri Lee

Jun Ho Kim

Kyeong Do Kim

A smart card with improved power stability is provided. The smart card comprises a rectification signal line through which a rectification signal extracted from a radio frequency (RF) signal is provided; a regulator configured to regulate a voltage of the rectification signal line to a first voltage; a power circuit configured to extract a power component from the rectification signal using an output of the regulator; a logic circuit configured to receive the power component and generate a reception enable signal on the basis of the power component; a demodulator which is enabled by the reception enable signal provided from the logic circuit and configured to extract a signal component from the rectification signal; a capacitor controller which is enabled by the reception enable signal provided from the logic circuit and configured to generate a capacitor enable signal; and a capacitor circuit which is connected to the rectification signal line and has capacitance changed according to the capacitor enable signal.

Smart card

Signal power management circuits and smart cards including the same are provided. For example, a signal power management circuit comprises a rectifier that is configured to rectify a received radio frequency signal and output a first rectified voltage, a first regulator that is configured to maintain the first rectified voltage at a predetermined first voltage level, and a second regulator that is configured to receive an output of the first regulator and maintain a second rectified voltage different from the first rectified voltage at a predetermined second voltage level. A signal detector of the signal power management circuit is configured to receive the first rectified voltage and the second rectified voltage and detect a signal component of the received radio frequency signal on the basis of a difference between the first voltage level of the first rectified voltage and the second voltage level of the second rectified voltage.

Growing community of inventors

Suwon-si, South Korea

Ju Ri Lee