An analog-to-digital converter including a first stage and a second stage. The first stage includes a first sample-and-hold (SH) having an input coupled to a voltage input node of the ADC, and having a first SH output. The first stage also includes a buffer, a first flash converter and a first digital-to-analog converter (DAC). The buffer has an input coupled to the first SH output and has a buffer output. The first flash converter has an input coupled to the first SH output, and has a first flash converter output. The first DAC has an input coupled to the first flash converter output. The second stage includes a second flash converter having an input coupled to the buffer output.

A gain calibration device for an ADC residue amplifier includes a DAC and a flash ADC. The DAC is configured to convert the digital signal to an analog signal, and the DAC includes a calibration module used in the gain calibration of the ADC residual amplifier. The flash ADC is configured to generate a digital signal, the flash ADC includes a plurality of comparators, the total number of the plurality of comparators is equal to the number of output bits of the flash ADC, and the comparators are configured to be unevenly distributed in an input range.

Systems and methods are provided for a successive approximation register (SAR) analog-to-digital converter (ADC) with an ultra-low burst error rate. Analog-to-digital conversions may be applied via a plurality of successive conversion cycles, with each conversion cycle corresponding to a particular bit in a corresponding digital output. Meta-stability may be detected during each one of the plurality of successive conversion cycles, and for each one of the plurality of successive conversion cycles, a next one of the plurality of successive conversion cycles may be triggered based on a cycle termination event. After completion of all of the plurality of successive conversion cycles, a meta-stability state of each of the plurality of successive conversion cycles may be assessed, and the digital output may be controlled based on the assessment.

An operational amplifier includes: a first gain stage for generating a second signal based on a first signal transmitted from a prior stage circuit; a second gain stage for generating an output signal based on the second signal; multiple candidate capacitors; and a capacitor selection circuit for switching the coupling relationship of the multiple candidate capacitors based on the magnitude of an input signal of the prior stage circuit, so that only a portion of the multiple candidate capacitors could be coupled to the second gain stage at a time.

An analog-to-digital converter (ADC) includes a first ADC stage with a first sub-ADC stage configured to sample the analog input voltage in response to a first phase clock signal and output a first digital value corresponding to an analog input voltage in response to a second phase clock signal. A current mode DAC stage is configured to convert the analog input voltage and the first digital value to respective first and second current signals, determine a residue current signal representing a difference between the first and the second current signal, and convert the residue current signal to an analog residual voltage signal. A second ADC stage is coupled to the first ADC stage to receive the analog residual voltage signal, and convert the analog residue voltage signal to a second digital value. An alignment and digital error correction stage is configured to combine the first and the second digital values.

A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a reference loading circuit uses a plurality of sampling switched capacitors connected in a switching configuration to selectively couple a first reference voltage and/or a second reference voltage to the central node by pre-charging the plurality of sampling switched capacitors with the first and second reference voltages during the sampling phase, and by coupling each of the first and second reference voltages to at least one of the plurality of sampling switched capacitors when connected to the central node during the gain phase.

An analog-to-digital converter (ADC) includes a first ADC stage with a first sub-ADC stage configured to output a first digital value corresponding to an analog input voltage. A current steering DAC stage is configured to convert the analog input voltage and the first digital value to respective first and second current signals, determine a residue current signal representing a difference between the first current signal and the second current signal in the current domain, and convert the residue current signal to an analog residual voltage signal. A second ADC stage is coupled to the first ADC stage to receive the analog residual voltage signal, and convert the analog residue voltage signal to a second digital value. An alignment and digital error correction stage is configured to combine the first and the second digital values into a digital output voltage.

Systems and methods are provided for enhanced analog-to-digital conversions, particularly by allowing for an ultra-low burst error rate. Analog-to-digital conversion may be applied to an analog input via one or more conversion cycles; and performance related parameter corresponding to the analog-to-digital conversion may be assessed. A digital output corresponding to the analog input may be generated, with the generating being controlled based on the assessing of the performance related parameter. The controlling may include adjusting at least a portion of the digital output. The assessing may include determining, for at least one conversion cycle, whether a performance related condition, corresponding to the performance related parameter, occurs. The determination may be based on an outcome of a matching search performed for that conversion cycle. The determination that the performance related condition occurs may be made when the matching search fails to settle within a corresponding time period.

An analog-to-digital converter including a first stage and a second stage. The first stage includes a first sample-and-hold (SH) having an input coupled to a voltage input node of the ADC, and having a first SH output. The first stage also includes a buffer, a first flash converter and a first digital-to-analog converter (DAC). The buffer has an input coupled to the first SH output and has a buffer output. The first flash converter has an input coupled to the first SH output, and has a first flash converter output. The first DAC has an input coupled to the first flash converter output. The second stage includes a second flash converter having an input coupled to the buffer output.

A sample-and-hold amplifier includes: a switched capacitor network for conducting a sample-and-hold operation on an input signal to generate a first signal; and an operational amplifier coupled with the switched capacitor network and including multiple candidate capacitors; wherein the operational amplifier is arranged to operably generate an output signal based on the first signal, and to operably switch coupling relationship of the multiple candidate capacitors based on the magnitude of the input signal, so that only a portion of the multiple candidate capacitors could be participated in the generation of the output signal at a time.