Analogue-to-digital converter, ADC, circuitry, including: an analogue input terminal; a comparator having first and second comparator-input terminals; and successive-approximation control circuitry to apply a potential difference across the first and second comparator-input terminals based on an input voltage signal, and to control the potential difference for a series of successive approximation operations to cause the comparator to test in each successive approximation operation whether a magnitude of an analogue input voltage signal is larger or smaller than a corresponding test value, the test value for each successive approximation operation being, dependent on a comparison result generated by the comparator in the preceding approximation operation, bigger or smaller than the test value for the preceding approximation operation by a difference amount configured for that successive approximation operation.

A plurality of comparison circuits each including a first terminal for inputting a first analog signal and a second analog signal and a second terminal connected to a wiring for transmission of a ramp signal A first operation changes an electric potential of the wiring from a predetermined electric potential to a first electric potential to cause at least one of the plurality of comparison circuits to retain a first offset. A second operation, after the first operation, converts the first analog signal into a digital signal. A third operation, after the second operation, changes the electric potential of the wiring to an electric potential included in a range of from the predetermined electric potential to the first electric potential. A fourth operation, after the third operation, converts the second analog signal into a digital signal.

An error correction method and a time-interleaved analog-to-digital converter (TIADC) are provided. The method is applied to a TIADC that includes a plurality of analog-to-digital converters (ADCs), and the method includes: determining whether a current value of a codeword of a first ADC in the plurality of ADCs is within a preset range; when the current value of the codeword of the first ADC is not within the preset range, adjusting a plurality of codewords that are in a one-to-one correspondence with the plurality of ADCs; and controlling a clock frequency division circuit to generate, by using a plurality of adjusted codewords, a plurality of sampling clocks that are in a one-to-one correspondence with the plurality of ADCs. In embodiments of this application, a sampling time-period skew existing between ADCs may be adjusted by adjusting codewords corresponding to the ADCs.

A successive approximation register (SAR) analog-to-digital converter (ADC) comprises a comparator for generating a comparison value according to an analog signal; a SAR, coupled to the comparator, comprises N memory units, each memory unit storing a control value and the N control values being related to the comparison value, N being an integer greater than two; and a thermometer-coded DAC, which generates the analog signal and is coupled to the comparator and the SAR. The thermometer-coded DAC comprises N capacitors. The N capacitors are respectively coupled to the N memory units. The N terminal voltages of the N capacitors are respectively controlled by the N control values.

A circuit includes a phase-locked loop having a phase-locked loop output to provide a first phase signal and a second phase signal phase delayed with respect to the first phase signal. The circuit further includes a digital circuit having a digital circuit input and an output. The digital circuit input couples to the phase-locked loop output. On the digital circuit output, the digital circuit is configured to provide a first digital-to-analog converter (DAC) enable signal and a second DAC enable signal. The circuit also includes first and second DACs. The first DAC is coupled to the digital circuit. The first DAC has a first enable input coupled to the digital circuit output to receive the first DAC enable signal. The second DAC is coupled to the digital circuit. The second DAC has a second enable input coupled to the digital circuit output to receive the second DAC enable signal.

An A/D conversion circuit includes a reference voltage source to generate a calibration voltage, a multiplexer to receive an analog signal and the calibration voltage, and output the analog signal selected in a normal mode and the calibration voltage selected in a calibration mode or a self-diagnosis mode, an A/D converter to convert an output signal from the multiplexer into a digital signal, a non-volatile memory to hold the digital signal and calibration data, a digital calibration part to calibrate the digital signal in case of inputting the analog signal to the A/D converter in the normal mode based on the calibration data, and a self-diagnosis circuit to diagnose the A/D converter based on the digital signal in case of inputting the calibration voltage to the A/D converter in the self-diagnosis mode, and the digital signal stored in the non-volatile memory.

A cyclic analog to digital converter for digitizing an output from a photoplethysmography sensor has a buffer amplifier for setting a voltage of the feedback capacitance. Additionally, digital averaging circuit is preferably provided for averaging the digital output from the cyclic analog to digital converter for the several conversions. Finally, voting logic is additionally provided for declaring the digital bits based on successive comparisons by the one or more comparators.

A circuit for receiving serial data. In some embodiments, the circuit has an input for receiving an analog input signal, and includes a first sampler for sampling the analog input signal relative to a first reference voltage, a second sampler for sampling the analog input signal relative to a second reference voltage, and a reference voltage control circuit. The second reference voltage may have a sign opposite to that of the first reference voltage; and the reference voltage control circuit may be configured to adjust the first reference voltage or the second reference voltage, based on a first sample of the analog input signal, the first sample having been taken at a sampling time corresponding to a one bit, in the serial data, preceded by a one bit and followed by a one bit.

An AD converter is provided with a control unit including a calibration control unit that controls an operation for calibrating the control unit and a conversion control unit that controls an operation for converting a target input voltage into a digital signal; a reference voltage unit that outputs a reference voltage; and an integrating converter unit including an integrating unit that generates an integrated voltage by integrating a predetermined unit voltage, a comparator that has two inputs and compares the integrated voltage and an input voltage or a reference voltage Vref, and a crossbar switch that switches connections between the case where the integrated voltage is inputted to one of the inputs of the comparator and the input voltage or the reference voltage Vref is inputted to the other input and the case where the input voltage or the reference voltage Vref is inputted to one of the inputs of the comparator and the integrated voltage is inputted to the other input.

Systems and methods are related to a successive approximation analog to digital converter (SAR ADC). The SAR ADC includes a sample and digital to analog conversion (DAC) circuit configured to sample an input voltage, a comparator circuit coupled to the sample and DAC circuit and having an output, a first set of storage circuits, and a comparator driver. The comparator driver is disposed between the output and the first set of storage circuits (e.g., ratioed latched. The first set of storage circuits are coupled to the comparator circuit and the sample and DAC circuit. The comparator driver can include a first driver and second driver. The first driver is coupled to a first input of a first storage circuit of the first set of storage circuits, and the second driver is coupled to first inputs of a second set of storage circuits within the first set of storage circuits.