Disclosed are an analog-to-digital converter error shaping circuit and a successive approximation analog-to-digital converter. The analog-to-digital converter error shaping circuit includes a decentralized capacitor array, a data weighted average module, a mismatch error shaping module, a control logic generation circuit, a digital filter and a decimator. The decentralized capacitor array includes two symmetrically arranged capacitor array units, each capacitor array unit includes a first sub-capacitor array of a high segment bit and a second sub-capacitor array of a low segment bit. The data weighted average module is configured to eliminate correlation between the first sub-capacitor array and an input signal, and the mismatch error shaping module is configured to eliminate correlation between the second sub-capacitor array and the input signal.

A high resolution analog to digital converter (ADC) with improved bandwidth senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. In addition, quantization noise is subtracted from the digital output signal thereby extending the operational bandwidth of the ADC. In certain examples, the operational bandwidth of the ADC extends up to 100s of kHz (e.g., 200-300 kHz), or even higher.

The present application discloses a successive approximation register analog-to-digital converter with passive noise shaping, which comprises: switch capacitor arrays for acquiring analog input signals; a noise shaping circuit which is a passive integral network, the network has input ends connected respectively with output ends of the two switch capacitor arrays and for acquiring output signals of the two switch capacitor arrays, is composed of a plurality of sub passive integrators, and reconfigures the plurality of sub passive integrators to different circuit forms; a comparator which has two input ends connected respectively with output ends of the passive integral network and an output end connected with an input end of a logic circuit, and is configured to compare magnitudes of the output signals of the noise shaping circuit.

Herein disclosed are some examples of metastability detectors and compensator circuitry for successive-approximation-register (SAR) analog-to-digital converters (ADCs) within delta sigma modulator (DSM) loops. A metastability detector may detect metastability at an output of a SAR ADC and compensator circuitry may implement a compensation scheme to compensate for the metastability. The identification of the metastability and/or compensation for the metastability can avoid detrimental effects and/or errors to the DSM loops that may be caused by the metastability of the SAR ADCS.

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.

In certain aspects, an analog-to-digital converter (ADC) includes a comparator having a first input, a second input, and an output. The ADC also includes a digital-to-analog converter (DAC) coupled to the first input of the comparator, a switching circuit, a first capacitor coupled between the first input of the comparator and the switching circuit, a second capacitor coupled between the first input of the comparator and the switching circuit, and an amplifying circuit having an input and an output, wherein the input of the amplifying circuit is coupled to the switching circuit. The ADC further includes a first switch coupled between the output of the amplifying circuit and the DAC, and a successive approximation register (SAR) having an input and an output, wherein the input of the SAR is coupled to the output of the comparator, and the output of the SAR is coupled to the DAC.

Provided is an AD converter, including: an analog signal input circuit, configured to be input with an analog input signal, and output a first analog output signal based on the analog input signal and a second analog output signal based on the analog input signal at different timing; an integral circuit, configured to integrate the first analog output signal and the second analog output signal and output the first integral signal and the second integral signal; a predictive circuit, configured to predict an integral signal output after the output by the integral circuit based on the first integral signal and the second integral signal output by the integral circuit, and output a predictive integral signal; and a quantization circuit, configured to generate a digital signal with the predictive integral signal quantized.

A system and method of replicating and cancelling chopping folding error in delta-sigma modulators. The modulator may include a loop filter coupled to a quantizer providing a digital signal, chopper circuitry that chops analog signals of the loop filter at a chopping frequency, and chopping folding error cancellation circuitry that replicates and cancels a chopping folding error of the chopper circuitry to provide a corrected digital signal. A digital chopper or multiplier chops the digital signal to provide a chopped digital signal, and the chopped digital signal is either amplified or multiplied by a gain value or digitally filtered to replicate the chopping folding error, which is then subtracted from the digital signal for correction. The timing and duty cycle of the chopping frequency may be adjusted. Timing and duty cycle adjustment may be calibrated along with the filtering.

An analogue-to-digital converter (ADC), comprising: an adaptive whitening filter configured to filter an analogue input signal and output a whitened analogue input signal; a first converter configured to receive said whitened analogue input signal and output a whitened digital signal; a controller configured to adapt the whitening filter based on the received analogue input signal.

This disclosure is directed to, among other things, techniques to decouple the number of bits in a quantizer from the number of bits in the feedback digital-to-analog converter (DAC). A delta-sigma analog-to-digital converter circuit can include a first quantizer to generate an output having a first number of bits and then emulate a second quantizer, such as by using a bit truncation technique, to generate an output having a second number of bits. The feedback DAC can be coupled to receive the second number of bits, where the output of the feedback digital-to-analog converter circuit has the second number of bits. These techniques can reduce the area of the feedback DAC, e.g., 4 or 5 bits, and the techniques can achieve a higher maximum stable amplitude (MSA) because it is effectively a second order loop.