Provided are a Time-Interleaved Successive Approximation Register Analog-to-Digital Converter, TISAR ADC, and a calibration method thereof. The calibration method for the TISAR ADC may include: sampling an analog signal input into the TISAR ADC to generate a reference digital signal (S130); according to the reference digital signal and output digital signals generated by analog-to-digital conversion sub-modules of the TISAR ADC, obtaining capacitor array calibration parameters and time delay calibration parameters of the analog-to-digital conversion sub-modules; adjusting capacitor arrays of the corresponding analog-to-digital conversion sub-modules according to the capacitor array calibration parameters, respectively; and adjusting time delays of the corresponding analog-to-digital conversion sub-modules according to the time delay calibration parameters, respectively.

Systems, apparatuses, and methods for performing digital pre-distortion compensation of digital-to-analog converter non-linearity are described. A correction circuit receives a digital input word and couples a portion of the most significant bits (MSB's) of the digital input word to a correction lookup table (LUT). A correction value is retrieved from a correction LUT entry that matches the MSB's of the digital input word. Next, the correction value is added to the original digital input word in the digital domain. Then, the sum generated by adding the correction value to the original digital input word is optionally clipped if the sum exceeds the DAC core's input range. Next, the DAC core converts the sum into an analog value that is representative of the digital input word. The above approach helps to reduce non-linearities introduced by the DAC core in an energy-efficient manner by performing a correction in the digital domain.

In accordance with the present invention a system and method for calibration of the current steering DAC is elaborated which helps to reduce design complexity and reduce silicon area required in the design. Present invention is utilising a clocked comparator and plurality of switch transistors 405,305 and AUX DAC in conjunction with digital estimator and digital compensator blocks to estimate the errors in the current sources 406 and compensate the errors using same AUX DAC during normal operation mode.

Aspects of the disclosure are directed to compensating for errors in in an analog-to-digital converter circuit (ADC). As may be implemented in accordance with one or more embodiments, an apparatus and/or method involves an ADC that converts an analog signal into a digital signal using an output from a digital-to-analog converter circuit (DAC). A compensation circuit generates a compensation output by, for respective signal portions provided to the DAC, generating a feedback signal based on an incompatibility between the conversion of the signal portions into an analog signal and the value of the signal portions provided to the DAC. A compensation output is generated based on the signal input to the DAC with a gain applied thereto, based on the feedback signal. Hereby, the digital inputs provided to the DACs are non-randomized.

A first and second input tone are applied to a continuous-time complex filter within an integrated circuit. The magnitude of the output of the filter at the frequency of each of the first and second input tones are measured and compared to determine the value of a filter tuning control signal. A tuning control signal is applied to the filter with the determined value to tune the filter.

The present disclosure provides an analog readout preprocessing circuit for a CMOS image sensor and a control method thereof. The analog readout preprocessing circuit comprises an extended count-type integration cycle-successive approximation hybrid analog-to-digital conversion capacitor network 1 configured to achieve readout and analog-to-digital conversion of signals output from the CMOS image sensor; an operational amplifier configured to utilize “virtual short” of two input terminals of the operational amplifier and the charge conservation principle, to achieve a function of extended count-type integration cycle-successive approximation hybrid analog-to-digital conversion, where the extended count-type integration can effectively reduce a thermal noise and a flicker noise within the image sensor; a comparator configured to compare voltages at two terminals to achieve a function of quantization of signals; and a control signal generator configured to provide control signals.

A scaling apparatus and method for compensating nonlinearity due to the finite output impedance of current sources in current-steering digital-to-analog converters (DACs) are disclosed herein. In an example, a DAC may receive a digital input signal. The DAC may determine an output current weight for each of a plurality of unit cells, based on an output impedance of the unit cell. Further, the DAC may generate an analog output signal by applying the plurality of output current weights to the digital input signal. Then, the DAC may output the analog output signal. The analog output signal may be a high frequency analog output signal, which may be an optical high frequency analog output signal. In an example, a transfer curve of the analog output signal may be linear in terms of analog output signal voltage versus digital input code. The output current weights may include one or more polynomial terms.

A multiplexer (MUX) calibration system includes main MUX circuitry, first replica MUX circuitry, digital-to-analog (DAC) circuitry, detection circuitry, and control circuitry. The main MUX circuitry receives clock signals and outputs a first data signal based on the clock signals. The first replica MUX circuitry receives the clock signals and outputs a second data signal based on the clock signals. The DAC circuitry generates an offset voltage. The detection circuitry receives the second data signal and the offset voltage and generates a first error signal based on one or more of the second data signal and the offset voltage. The control circuitry receives the first error signal and generates a first control signal indicating an adjustment to the clock signals.

An analog to digital converter temperature compensation system comprising a comparator configured to compare an analog input signal to a compensated feedback signal and generate a comparator output. A SAR module processes the comparator output to generate a digital signal. A digital to analog converter, biased by a biasing signal having temperature change induced error, is configured to convert the digital signal to a feedback signal and a detector is configured to detect a signal that is proportional to temperature. A look-up table is configured to receive and convert the signal that is proportional to temperature to a compensation signal such that the compensation signal compensates for the temperature change induced error in the biasing signal. A summing node combines the feedback signal with the compensation signal to create a compensated feedback signal.

An analog-to-digital converter (ADC) circuit includes a signal input terminal, a sample-and-hold circuit, and a successive approximation register (SAR) ADC. The sample-and-hold circuit includes an input terminal coupled to the signal input terminal. The SAR ADC includes a comparator, a first capacitive digital-to-analog converter (CDAC), and a second CDAC. The first CDAC includes a first input terminal coupled to the signal input terminal, a second input terminal coupled to an output terminal of the sample-and-hold circuit, and an output terminal coupled to a first input terminal of the comparator. The second CDAC includes a first input terminal coupled to the signal input terminal, an output terminal coupled to a second input terminal of the comparator.