A dual-loop analog to digital converter (ADC) includes an asynchronous inner loop including first and second comparators and a state machine, where outputs of the first and second comparators are coupled to inputs of the state machine, and where outputs of the state machine are cross-coupled to enable ports of the first and second comparators. The ADC includes a synchronous outer loop including a successive approximation register (SAR), a digital to analog converter (DAC), and the first and second comparators, where the outputs of the first and second comparators are coupled to inputs of the SAR, an N-bit output of the SAR is coupled to an N-bit input of the DAC, and a differential output of the DAC is coupled to inputs of the first and second comparators, where a state of the state machine is independent of the state of the SAR.

Herein disclosed is an example analog-to-digital converter (ADC) and methods that may be performed by the ADC. The ADC may derive a first code that approximates a combination of an analog input value of the ADC and a dither value for the ADC sampled on a capacitor array. The ADC may further derive a second code to represent a residue of the combination with respect to the first code applied to the capacitor array. The ADC may combine the numerical value of the first code and the numerical value of the second code to produce a combined code applied to the capacitor array for deriving a digital output code. Combining the numerical value of the first code and the numerical value of the second code in the digital domain can provide for greater analog-to-digital (A/D) conversion linearity.

A method of operating an analog-to-digital converter includes in a first sampling stage, switching a swap signal to a first level for a first selection circuit to reset a first capacitor array according to a first voltage configuration and for a second selection circuit to reset a second capacitor array according to the first voltage configuration, and in a second sampling stage, switching the swap signal to a second level for the first selection circuit to reset the first capacitor array according to the second voltage configuration and for the second selection circuit to reset the second capacitor array according to the second voltage configuration. A control logic circuit is used to switch the swap signal between the first level and the second level in a uniform order in a plurality of sampling stages.

An N-channel interleaved Analog-to-Digital Converter (ADC) has a variable delay added to each ADC's input sampling clock. The variable delays are each programmed by a Successive-Approximation-Register (SAR) during calibration to minimize timing skews between channels. An auto-correlator generates a sign of a correlation error for a pair of ADC digital outputs. SAR bits are tested with the correlation sign bit determining when to add or subtract SAR bits. First all pairs are calibrated in a first level of a binary tree of mux-correlators. Then skews between remote pairs and groups are calibrated in upper levels of the binary tree using auto-correlators with inputs muxed from groups of ADC outputs input to the binary tree of mux-correlators. The binary tree of mux-correlators can include bypasses for odd and non-binary values of N. Sampling clock and component timing skews are reduced to one LSB among both adjacent channels and remote channels.

An analog-to-digital converter is provided. An analog-to-digital converter includes a comparator including a first input node receiving an output of a plurality of first unit capacitors and a second input node receiving an output of a plurality of second unit capacitors, a control logic configured to output first and second control signals on the basis of an output signal of the comparator, and a reference voltage adjustment circuit configured to adjust an output voltage provided to the comparator on the basis of the first and second control signals. The reference voltage adjustment circuit comprises a first pull-up circuit configured to apply a first reference voltage to each of the plurality of first unit capacitors and a first pull-down circuit configured to apply a second reference voltage to each of the plurality of second unit capacitors, based on v.

An analog-to-digital converter, configured to convert an input signal into an n bits digital output signal, includes a capacitor module, a control signal generation unit, a comparator, and a register. The capacitor module is configured to receive the input signal at a sampling phase in a normal mode, and to generate a first sampling signal and a second sampling signal according to the input signal in a conversion phase. The control signal generation unit is configured to adjust the first sampling signal or the second sampling signal in the conversion phase. In the normal mode, the comparator is configured to compare the first sampling signal and the second sampling signal in the conversion phase to generate n comparison signals. The register is configured to store the n comparison signals as the digital output signal, and output the digital output signal in the normal mode.

A successive-approximation register analog-to-digital converter (SAR ADC), a correction method and a correction system are provided. The SAR ADC generates an original weight value sequence according to multiple original weight values. The SAR ADC converts an analog time-varying signal to establish a transforming curve corresponding to the original weight values. In addition, the SAR ADC generates an offset value sequence according to an offset of the transforming curve, uses the offset value sequence to correct the original weight value sequence to generate a corrected weight value sequence, and uses multiple corrected weight values of the corrected weight sequence to improve linearity of the transforming curve.

A successive-approximation register analog-to-digital converter (SAR ADC), a correction method and a correction system are provided. The SAR ADC generates an original weight value sequence according to multiple original weight values. The SAR ADC converts an analog time-varying signal to establish a transforming curve corresponding to the original weight values. In addition, the SAR ADC generates an offset value sequence according to an offset of the transforming curve, uses the offset value sequence to correct the original weight value sequence to generate a corrected weight value sequence, and uses multiple corrected weight values of the corrected weight sequence to improve linearity of the transforming curve.

A reference voltage generator comprises a comparator, a digital-to-analog converter (DAC) and a switched capacitor accumulator. The comparator receives a reference voltage input, a feedback input, and a control signal. The DAC is coupled to an output of the comparator, and the switched capacitor accumulator is coupled to an output of the DAC. In some implementations, a digital filter is coupled between the output of the comparator and the input of the DAC. The switched capacitor accumulator can be coupled to a buffer that outputs the feedback input and a reference voltage for an analog-to-digital converter (ADC). In some implementations, the feedback loop includes N one-bit DACs coupled to the output of the comparator and N switched capacitor accumulators, each of which is coupled to a unique one-bit DAC.

An analog-to-digital converter (ADC) is provided. In some examples, the ADC includes a first reference voltage supply input, a second reference voltage supply input, a comparator comprising an input node, and a first reference switch coupled between the second reference voltage supply input and the input node of the comparator. The ADC also includes a set of capacitors, where each capacitor of the set of capacitors comprises a first terminal. In addition, the ADC includes a second reference switch coupled between the first reference voltage supply input and the first terminal of each capacitor of the set of capacitors. The ADC further includes a third switch coupled between the input node of the comparator and the first terminal of each capacitor of the set of capacitors.