A multi-input analog-to-digital converter (ADC), i.e., a single ADC, can receive multiple analog input signals and generate multiple digital outputs. To combine multiple analog input signals into a single multi-input ADC, the multi-input ADC would typically include multiple track and hold (T/H) circuits and an adder, which can consume a significant amount of power and incur large cost overhead. An improved approach is to combine multiple inputs through a unique T/H circuit in the front-end of the ADC. The multiple analog input signals can be aggregated using code sequences, without requiring a significant amount of external circuits.

Single-stage and multiple-stage current-mode Analog-to-Digital converters (iADC)s utilizing apparatuses, circuits, and methods are described in this disclosure. The disclosed iADCs can operate asynchronously and be free from the digital clock noise, which also lowers dynamic power consumption, and reduces circuitry overhead associated with free running clocks. For their pseudo-flash operations, the disclosed iADCs do not require their input current signals to be replicated which saves area, lowers power consumption, and improves accuracy. Moreover, the disclosed methods of multi-staging of iADCs increase their resolutions while keeping current consumption and die size (cost) low. The iADC's asynchronous topology facilitates decoupling analog-computations from digital-computations, which helps reduce glitch, and facilitates gradual degradation (instead of an abrupt drop) of iADC's accuracy with increased input current signal frequency. The iADCs can be arranged with minimal digital circuitry (i.e., be digital-light), thereby saving on die size and dynamic power consumption.

An analog to digital converter is disclosed that is designed to receive a differential analog signal and includes a signal chopping circuit and a successive approximation register (SAR) coupled to the signal chopping circuit. The signal chopping circuit is designed to invert a polarity of the differential analog signal and includes a first switching circuit having a first transistor and a second switching circuit having a second transistor. A gate of the first transistor and a gate of the second transistor is each coupled to a same bootstrap capacitor. Coupling both switching circuits to the same bootstrap capacitor (as opposed to separate bootstrap capacitors) greatly frees up space on the die or chip.

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.

An integrated circuit is described. The integrated circuit comprises an analog-to-digital converter circuit configured to receive an input signal at an input and generate an output signal at an output; and a monitor circuit coupled to the output of the analog-to-digital converter circuit, the monitor circuit configured to receive the output signal and to generate integration coefficients for the analog-to-digital converter circuit; wherein the integration coefficients are dynamically generated based upon signal characteristics of the output signal generated by the analog-to-digital converter circuit. A method of receiving data in an integrated circuit is also described.

Capacitor arrays and methods of operating a digital to analog converter are described. In an embodiment, a capacitor array includes a unit capacitor (Cu) structure characterized by a unit capacitance value, a plurality of different super-unit capacitor structures, and a plurality of different sub-unit capacitor structures, each different sub-unit capacitor structure having a different capacitance defined by a division of the unit capacitance value.

A device for noise suppression and distortion correction of analog-to-digital converters based on deep learning that realizes effect of correcting noise and distortion of analog to digital converters. The method is applied to electronic ADCs or photonic ADCs. It utilizes the learning ability of the deep network to perform system response learning on ADCs which need noise suppression and distortion correction, establishes a computational model in the deep network that can suppress the reconstruction of noises and distorted signals, performs noise suppression and distortion correction on the signals obtained by ADCs, and thereby improves performance of the learned ADCs. The device improves the performance of the microwave photon system with high sampling precision of microwave photon radar and optical communication system.

A time-interleaved SAR-ADC employs calibrated SAR-ADC circuits to convert sampled voltage levels into serial digital data. Variable delay clock circuits synchronize clock signals received at the respective SAR-ADCs to sampling points of analog serial data. IC and environmental fluctuations cause delay in the variable delay clock circuits to skew the clock signals. A calibrated SAR-ADC detects changes to the delays in the variable delay clock circuits. By delaying a first clock signal in the variable delay clock circuit, and comparing a phase of the delayed clock signal to a phase-shifted clock signal having a known phase shift relative to the first clock signal, a change in the delay of the variable delay clock circuit can be detected as a phase difference. Based on an indication of a phase difference, a delay control signal is generated to control the delay in the variable delay clock.

Various embodiments of the present technology may provide methods and apparatus for a successive approximation register analog-to-digital converter (SAR ADC). The SAR ADC may provide a first digital calibration circuit configured to correct systemic mismatch and a second digital calibration circuit configured to correct random mismatch. Together, the first and second digital calibration circuits resolve missing codes in the SAR ADC output.

An apparatus for calibrating an analog-to-digital converter is provided. The apparatus includes a reference input generation circuit configured to subsequently generate two reference inputs for calibrating the analog-to-digital converter. The two reference inputs both represent ramp waveforms, wherein the ramp waveforms represented by the two reference inputs are different from each other. Further, the apparatus includes a coupling circuit configured to controllably couple an input node of the analog-to-digital converter to either the reference input generation circuit or to a signal node capable of providing an analog input for digitization.