Analog to digital conversion circuitry has an input sampling buffer, which has an input sampling capacitor for sampling an analog signal. The conversion circuitry also has a successive-approximation-register analog to digital converter (SAR-ADC) which converts the sampled analog signal to a digital signal. The input sampling buffer has an amplifier and a gain-control capacitor, and has an amplification configuration and an error-feedback configuration. In the amplification configuration, the input sampling capacitor is coupled to the amplifier and gain-control capacitor, with the gain-control capacitor connected in feedback with the amplifier, for applying gain to the sampled analog signal. In the error-feedback configuration, the gain-control capacitor is decoupled from the input sampling capacitor and receives a residue voltage from the SAR-ADC, such that the level of the analog signal determined in the amplification configuration varies depending on the residue voltage received onto the gain-control capacitor in the error-feedback configuration.

An offset-cancellation circuit having a first amplification stage with a gain of the first amplification stage and configured to receive an offset voltage of a first amplifier. A storage element is configured to be coupled to and decoupled from the first amplification stage and configured to store a potential difference output by the first amplification stage. The potential difference is determined by the offset voltage of the first amplifier and the gain of the first amplification stage. A second amplification stage is coupled to the storage element and configured to receive the potential difference from the storage element when the storage element is decoupled from the first amplification stage and configured to deliver an offset-cancellation current. The offset-cancellation current is determined by the potential difference and a gain of the second amplification stage.

A method for operating an input device, the method involving obtaining a number of non-sinusoidal transmitter signals with unique base frequencies, and selecting a sampling frequency of an analog-to-digital converter (ADC) such that a number of aliasing artifacts associated with higher harmonics of the non-sinusoidal transmitter signals is located at frequencies different from the base frequencies.

An Analog-to-Digital Converter, ADC, system is provided. The ADC system comprises a plurality of ADC circuits and a first input for receiving a transmit signal of a transceiver. One ADC circuit of the plurality of ADC circuits is coupled to the first input and configured to provide first digital data based on the transmit signal. The ADC system further comprises a second input for receiving a receive signal of the transceiver. The other ADC circuits of the plurality of ADC circuits are coupled to the second input, wherein the other ADC circuits of the plurality of ADC circuits are time-interleaved and configured to provide second digital data based on the receive signal. Additionally, the ADC system comprises a first output configured to output digital feedback data based on the first digital data, and a second output configured to output digital receive data based on the second digital data.

A method to implement hybrid signal processing includes steps for receiving an analog signal at a receiver frontend, sampling the received analog signal and storing the analog sampled signals using a plurality of sampling circuitries inside the receiver frontend. Then, processing the plurality of analog sampled signals using interleaved feed-forward equalizers (FFEs) to provide FFE interleaved sampled signal values corresponding to each of the sampling circuitries. Then, processing the analog sampled signals at an interleaved Decision Feedback Equalizer (DFE) to obtain DFE interleaved sampled signal values, summing each of the FFE interleaved sampled signal values with output from one of the DFE interleaved sampled signal values to provide equalizer output signal values, and digitizing the equalizer output signal values to provide digital data bits corresponding to each of the equalizer output signal values. Implementations of the method as a hybrid communication system, system-on-a-chip, and computer readable memory are also disclosed.

An analog input device, which converts an inputted analog signal to a digital signal and outputs the digital signal, includes a high resolution AD converter, a first low resolution AD converter, and a second low resolution AD converter. When a difference between a first digital signal converted by the high resolution AD converter and a second digital signal converted by the first low resolution AD converter is equal to or less than a predetermined first threshold, the analog input device outputs first digital signal. When the difference between the first digital signal and the second digital signal is larger than the predetermined first threshold, the analog input device stops an output of the first digital signal.

An analog-to-digital converter includes a switch circuit, a first capacitor array, a second capacitor array and a comparator. A method of operating the analog-to-digital converter includes switching a swap signal to a first level in a first sampling period for the switch circuit to couple the first capacitor array to a first input terminal of the comparator and a first signal source, and couple the second capacitor array to a second input terminal of the comparator and a second signal source, and switching the swap signal to a second level in a second sampling period for the switch circuit to couple the first capacitor array to the second input terminal of the comparator and the second signal source, and couple the second capacitor array to the first input terminal of the comparator and the first signal source.

A method of operating an analog-to-digital converter includes in a first conversion period, a comparator generating a first comparison result, a first selection circuit switching a voltage output to a first capacitor of a set of larger capacitor of a first capacitor array, and a second selection circuit switching a voltage output to a second capacitor of a set of larger capacitor of a second capacitor array, and in a second conversion period after the first conversion period, the comparator generating a second comparison result different from the first comparison result, the first selection circuit switching back the voltage output to a first capacitor portion of the first capacitor of the set of larger capacitor of the first capacitor array, and the second selection circuit switching back the voltage output to a first capacitor portion of the second capacitor of the set of larger capacitor of the second capacitor array.

A system and method for detecting an anomaly in a structure using an adaptive filter to compensate for variations in piezoelectric transducer performance due to environmental factors such as temperature. A first voltage signal having a first amplitude is sent to a reference piezoelectric actuator. Thereafter, a first reference voltage signal is received from a reference piezoelectric receiver which is acoustically coupled to detect the guided wave generated by the reference piezoelectric actuator. A second amplitude is determined using an optimization algorithm of an adaptive filter to compensate for nonlinear behavior of the reference piezoelectric actuator and receiver based on the first reference voltage signal. Then the adaptive filter sends a second voltage signal having the second amplitude to the reference and test piezoelectric actuators. Reference and test voltage signals are received from the reference and test piezoelectric receivers in response to the second voltage signal. A difference voltage signal representing differences between the reference and test voltage signals received is then recorded.

An estimate of unit current element mismatch error in a digital to analog converter circuit is obtained through a correlation process. Unit current elements of the digital to analog converter circuit are actuated by bits of a thermometer coded signal generated in response to a quantization output signal. A correlation circuit generates the estimates of the unit current element mismatch error from a correlation of a first signal derived from the thermometer coded signal and a second signal derived from the quantization output signal.