A method is described that is performed by a calibration system. The method includes determining a set of perturbation values for configuring an analog-to-digital converter of the calibration system; generating a set of digital test values for determining the accuracy of the analog-to-digital converter; and applying the set of perturbation values to the set of digital test values to generate a set of modified test values, wherein the set of perturbation values are digital values that are applied to the set of digital test values in the digital domain.

An analog to digital converter (ADC) device includes ADC circuits, a calibration circuit, and a skew adjusting circuit. The ADC circuits convert an input signal according to interleaved clock signals, in order to generate first quantized outputs. The calibration circuit performs at least one calibration computation according to the first quantized outputs to generate second quantized outputs. The skew adjusting circuit determines calculating signals, to which the second quantized outputs correspond in a predetermined interval, and averages the calculating signals to generate a reference signal, and compares the reference signal with each of the calculating signals to generate detecting signals, and determines whether the detecting signals are adjusted or not according to a signal frequency to generate adjusting signals, in order to reduce a clock skew in the ADC circuits.

Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.

The present disclosure provides a linear calibration system for a time-to-digital converter and a method thereof, and a digital phase-locked loop. The linear calibration system includes a digitally controlled reference delay circuit for receiving a first clock signal and delaying the first clock signal to generate a reference clock signal, a time-to-digital conversion circuit including at least two time-to-digital converters, and a state machine. The time-to-digital conversion circuit receives the first clock signal and the reference clock signal, delays the first clock signal to generate a first delay signal, compares a phase of the first delay signal with a phase of the reference clock signal, and outputs a phase detection result signal. The state machine generates a delay control signal for controlling the digitally controlled reference delay circuit, adjusts a calibration control signal to align the phases of the first delay signal and the reference clock signal.

An analog to digital converter (ADC) device includes ADC circuits, a calibration circuit, and a skew adjusting circuit. The ADC circuits are configured to convert an input signal according to interleaved clock signals to generate first quantized outputs. The calibration circuit is configured to perform at least one calibration operation according to the first quantized outputs to generate second quantized outputs. The skew adjusting circuit further includes a first adjusting circuit. The first adjusting circuit is configured to analyze adjacent clock signals according to part of the second quantized outputs to generate adjusting information. The skew adjusting circuit is configured to analyze time difference information within even-numbered sampling periods of the clock signals according to the second quantized outputs and the adjusting information to generate adjustment signals. The adjustment signals are configured to reduce clock skews of the ADC circuits.

An analog to digital converter (ADC) device includes ADC circuits, a calibration circuit, and a skew adjusting circuit. The ADC circuits convert an input signal according to interleaved clock signals, in order to generate first quantized outputs. The calibration circuit performs at least one calibration computation according to the first quantized outputs to generate second quantized outputs. The skew adjusting circuit determines calculating signals, to which the second quantized outputs correspond in a predetermined interval, and averages the calculating signals to generate a reference signal, and compares the reference signal with each of the calculating signals to generate detecting signals, and determines whether the detecting signals are adjusted or not according to a signal frequency to generate adjusting signals, in order to reduce a clock skew in the ADC circuits.

An analog to digital converter (ADC) device includes ADC circuits, a calibration circuit, and a skew adjusting circuit. The ADC circuits convert an input signal according to interleaved clock signals, in order to generate first quantized outputs. The calibration circuit performs at least one calibration computation according to the first quantized outputs to generate second quantized outputs. The skew adjusting circuit determines maximum value signals, to which the second quantized outputs correspond in a predetermined interval, and averages the maximum value signals to generate a reference signal, and compares the reference signal with each of the maximum value signals to generate detecting signals, and determines whether the detecting signals are adjusted or not according to a signal frequency to generate adjusting signals, in order to reduce a clock skew in the ADC circuits.

Examples describe a switched capacitor (SC) circuitry calibrated to mitigate the pole-zero (PZ) doublet errors that occur in an analog circuitry. Due to PZ-doublet errors, the slow settling time response of an input step function to an analog circuitry make it impractical to use in applications such as a digital oscilloscope. Mitigating the PZ-doublet errors in the frequency domain is not practical due to the problem of the generation of low frequency sinusoidal tones. The solution disclosed in the present invention is to apply a step function and examine the output's slow settling error waveform. A signal is input to an analog to digital converter, and the output of the converter is processed by a computation that produces calibration codes. Calibration codes are coupled to a SC circuitry to mitigate the PZ-doublet errors. The error waveform is then minimized within a specified accuracy.

The present application discloses a data converter (112). The data converter includes an input terminus (98), a digital-to-analog (D/A) converter (116) and a mapping unit (114). The input terminus is configured to receive an input signal. The D/A converter includes a plurality of D/A converter units configured to generate an output signal. The mapping unit is coupled between the input terminus and the D/A converter and is configured to cause the plurality of D/A conversion units to be equivalently arranged in a relative order in which the plurality of D/A conversion units are gated according to specific electrical characteristics of the plurality of D/A conversion units for digital-to-analog conversion. The present application further provides an A/D converter, a D/A converter and a related chip.

A n-bit Successive Approximation Register Analog-to-Digital Converter, SAR ADC, is provided. The SAR ADC comprises a respective plurality of sampling cells for each bit of the n-bit of the SAR ADC. Each sampling cell comprises a capacitive element coupled to a cell output of the sampling cell in order to provide a cell output signal. Further, each sampling cell comprises a first cell input for receiving a first signal, and a first switch circuit capable of selectively coupling the first cell input to the capacitive element. Each cell additionally comprises a second cell input for receiving a second signal, and a third cell input for receiving a third signal. The third signal exhibits opposite polarity compared to the second signal. Each sampling cell comprises a second switch circuit capable of selectively coupling one of the second cell input and the third cell input to the capacitive element. The SAR ADC further comprises at least one comparator circuit coupled to the sampling cells. The at least one comparator circuit is configured to output a comparison signal based on the cell output signals of the sampling cells. Additionally, the SAR ADC comprises a calibration circuit configured to supply at least one respective control signal to the respective second switch circuit of the sampling cells for controlling the second switch circuits.