The present disclosure provides systems and devices including reception circuits for communications between smart cards and card readers. In some embodiments, a reception circuit of a smart card includes a first circuit and a second circuit. The first circuit is configured to receive a wireless signal including a pause, and restore the wireless signal to a clock signal. The second circuit is configured to charge a voltage of a first node based on a first logic level of the clock signal, compare the voltage of the first node with a predefined reference voltage, and output, based on the comparison of the voltage of the first node, a synchronization signal indicating a rising starting time point of the pause of the wireless signal.

A smart card includes a frequency measurement circuit configured to measure a first clock frequency of an external clock signal, a sensor clock output circuit configured to select a first range from a plurality of first clock ranges based on the first clock frequency and to output a sensor clock signal having a second clock frequency corresponding to the first range, and a sensor circuit configured to output sensing data for biometric authentication based on the sensor clock signal and first compensation image data.

A method includes receiving image information related to a first plurality of pixels at a first data pathway, receiving image information related to a second plurality of pixels at a second data pathway, where the first plurality of pixels and the second plurality of pixels include a shared plurality of pixels. The method also includes performing image processing in dependence on image information related to the shared plurality of pixels, and combining data output from the first and second data pathways into a stream of data where the stream output is generated using a first clock frequency which is substantially the same as that used in the first and second data pathways.

The present disclosure provides systems and devices including reception circuits for communications between smart cards and card readers. In some embodiments, a reception circuit of a smart card includes a first circuit and a second circuit. The first circuit is configured to receive a wireless signal including a pause, and restore the wireless signal to a clock signal. The second circuit is configured to charge a voltage of a first node based on a first logic level of the clock signal, compare the voltage of the first node with a predefined reference voltage, and output, based on the comparison of the voltage of the first node, a synchronization signal indicating a rising starting time point of the pause of the wireless signal.

A smart card includes a frequency measurement circuit configured to measure a first clock frequency of an external clock signal, a sensor clock output circuit configured to select a first range from a plurality of first clock ranges based on the first clock frequency and to output a sensor clock signal having a second clock frequency corresponding to the first range, and a sensor circuit configured to output sensing data for biometric authentication based on the sensor clock signal and first compensation image data.