An apparatus and a method for recovering clock and data from a multilevel pulse amplitude modulated signal received as input signal is suggested. The apparatus comprises a phase detector, a low-pass filter, a voltage-controlled oscillator, and a feedback loop forming a CDR loop. The voltage-controlled oscillator outputs a clock signal that is provided to the phase detector. The phase detector receives an MSB signal from a sampler. The apparatus also comprises an interleave circuit configured to receive the input signal and to generate two output signals having a smaller symbol rate than the input signal. The apparatus further comprises a logical gate configured to receive the output signals from the interleave circuit and to generate an enable signal for the phase detector indicating symmetrical transitions in the input signal. Lastly, the apparatus comprises a converter converting the output signals from the interleave circuit into an MSB and an LSB bit stream.

A transceiver of the present inventive concept includes a transmitter and a receiver connected by a first line and a second line, and the transmitter includes a first encoder; a second encoder; and a transmission driver. The first encoder generates a first encoded data different from a first data during a first period and the second encoder generates a second encoded data equal to a second data during the first period, the second encoder generates the second encoded data different from the second data during a second period and the first encoder generates the first encoded data equal to the first data during the second period, and the first period and the second period are arranged to alternate with each other.

A power feeding apparatus is provided. The power feeding apparatus includes a power feeding unit configured to supply electric power to a power receiving apparatus through a magnetic field; a measuring unit configured to measure an electric characteristic value and to generate a measurement value; a power receiving unit configured to provide a set value; and a foreign substance detection unit configured to detect a foreign substance in the magnetic field based on the set value and the measurement value. A power receiving apparatus, a power feeding system, and a method of controlling power feeding are also provided.

A transmission device of the disclosure includes: a generator unit that generates, on the basis of a control signal, a transmission symbol signal that indicates a sequence of transmission symbols; an output control unit that generates an output control signal on the basis of the transmission symbol signal; and a driver unit that generates, on the basis of the output control signal, a first output signal, a second output signal, and a third output signal. The generator unit generates the transmission symbol signal on the basis of the control signal, to allow the first output signal, the second output signal, and the third output signal to exchange signal patterns with one another.

Methods in an optical receiver, for decoding a received M-level pulse-amplitude-modulated, PAM-M, optical signal. An example method comprises, for a first interval, decoding (510) the received PAM-M optical signal using a standard PAM-M decoder with M-1 thresholds, using first sampling times, to obtain a first set of decoded bits, and decoding (520) the received PAM-M optical signal using a duobinary decoder with 2M-2 thresholds, at second sampling times offset from the first sampling times, to obtain second set of decoded bits. The method further comprises calculating (530) first and second error metrics corresponding to the first and second sets of decoded bits, respectively, and selecting (540) the standard PAM-M decoder or the duobinary decoder for subsequent decoding of the received PAM-M optical signal, based on the first and second error metrics.

A signal transmitting device includes an output control circuit and a transmitting circuit. The output control circuit generates a first encoded symbol, a second encoded symbol, a third encoded symbol, and a fourth encoded symbol and an inverted flag signal by inverting the logic levels of second bits of a first symbol, a second symbol, a third symbol, and a fourth symbol, and generates a first output control signal and a second output control signal based on the first to fourth encoded symbols, when the maximum transition is present among the first to fourth symbols. The transmitting circuit may transmit the inverted flag signal and a Tx (Transmit) signal generated based on the first and second output control signals.

An offset detector circuit includes a digital signal register storing M unit digital signals received in latest M signal periods, M being a natural number, among digital signals generated based on a single-ended PAM-N signal, N being an odd number, a comparator outputting a comparison signal of a pair of signals included in differential signals generated from a differential signal generator based on the single-ended PAM-N signal, a comparison result register storing M unit comparison signals corresponding to the latest M signal periods among the comparison signals, a pattern detector outputting a detection signal when the M unit digital signals match a predetermined signal pattern, and an offset checker checking patterns of the M unit comparison signals in response to the detection signal, and outputting an offset detection signal when the patterns of the M unit comparison signals match a predetermined offset pattern.

A semiconductor device including a comparison circuit configured to receive an input signal having n signal levels, where n is a natural number equal to or greater than three, and output n-1 first signals having two signal levels. The device includes a jitter compensation circuit configured to receive the n-1 first signals and compensate for at least one of a length of a period in which a signal level of at least one of the n-1 first signals transitions from a first signal level to a second signal level different from the first signal level, and a length of a period in which the signal level of the at least one of the n-1 first signals transitions from the second signal level to the first signal level, to output n-1 second signals.

A transmission device of the disclosure includes: a generator unit that generates, on the basis of a control signal, a transmission symbol signal that indicates a sequence of transmission symbols; an output control unit that generates an output control signal on the basis of the transmission symbol signal; and a driver unit that generates, on the basis of the output control signal, a first output signal, a second output signal, and a third output signal. The generator unit generates the transmission symbol signal on the basis of the control signal, to allow the first output signal, the second output signal, and the third output signal to exchange signal patterns with one another.

Quantization noise in an oversampled eddy current digital drive circuit is reduced using a noise shaping filter.