An ADC circuit (50) is disclosed. It comprises a global input configured to receive an input voltage (V.sub.in) and a plurality of converter circuits (105.sub.1-105.sub.N). Each converter circuit (105.sub.j) comprises a comparator circuit (70.sub.j) having a first input connected to the global input, a second input, and an output configured to output a one-bit output signal of the comparator circuit (70.sub.j). Furthermore, each converter circuit (105.sub.j) comprises a one-bit current-output DAC (110.sub.j) having an input directly controlled from the output of the comparator circuit (70.sub.j) and an output connected to the second input of the comparator circuit (70.sub.j). The second inputs of all comparator circuits are interconnected. The ADC circuit (50) further comprises a digital output circuit (130) configured to generate an output signal z[n] of the ADC circuit (50) in response to the one-bit output signals of the comparator circuits (70.sub.j).

An ADC system dynamically adjusts threshold levels used to resolve PAM signal amplitudes into digital values. The ADC circuitry includes an analog front end to receive and condition the PAM signal, a low-resolution ADC to digitize the conditioned signal according to a first set of threshold values, and a high-resolution ADC to subsample the conditioned signal to generate subsampled signals. A microprocessor in communication with the low-resolution ADC and the high-resolution ADC derives a statistical value from the subsampled signals, determines an updated set of threshold values, and dynamically replaces the first set of threshold values for the low-resolution ADC with the updated set of threshold values.

An analog-to-digital circuit that digitizes an analog voltage. The analog-to-digital circuit includes plural comparators functionally connected to form a tree that has levels i, and each level i has branches j, and an encoder connected to the plural comparators and configured to generate a digitized value of an input analog voltage. Each comparator from a level i has first and second outputs, and each of the first and second outputs is electrically connected to an input of different comparators from a next level i+1 of the tree.

Provided is an analog to digital converter configured to receive a continuous input signal. The analog to digital converter includes an integrating block, comprising at least an integrating stage, which output is coupled to a flash analog to digital converter. The analog to digital converter apparatus includes a feedback path coupled to the output of said flash analog to digital converter. The feedback path includes at least a digital to analog conversion block which output is compared at least to the input signal to obtain an error signal which is brought as input to said integrating block. A control block is configured to perform control comprising at least a digital integration, is coupled between the output of said flash analog to digital converter and said feedback path.

An apparatus configured to convert an analog input signal into a digital output signal may include a first amplification circuit configured to receive the analog input signal and a plurality of reference voltages and amplify differences between the analog input signal and the plurality of reference voltages; a plurality of first capacitors configured to respectively store charges corresponding to signals outputted by the first amplification circuit; a second amplification circuit configured to amplify differences among voltages of the plurality of first capacitors; a plurality of second capacitors configured to respectively store charges corresponding to signals outputted by the second amplification circuit; and a comparison circuit configured to generate the digital output signal by comparing voltages of the plurality of second capacitors with each other.

An apparatus for analog-to-digital conversion is provided. The apparatus includes a first analog-to-digital converter (ADC) configured to receive an input signal and convert the input signal to a sequence of M-bit digital values. The apparatus further includes a second ADC including a plurality of time-interleaved sub-ADCs each being configured to receive the input signal and at least one M-bit digital value of the sequence of M-bit digital values. Further, each of the plurality of time-interleaved sub-ADCs is configured to convert the input signal to a respective sequence of B-bit digital values using the at least one M-bit digital value of the sequence of M-bit digital values. M and B are integers with M<B.

Technologies relating to implementing two-stage ramp ADCs in crossbar array circuits for high performance matrix multiplication are disclosed. An example two-stage ramp ADC includes: a transimpedance amplifier configured to convert an input signal from current to voltage; a comparator connected to the transimpedance amplifier; a switch bias set connected to the comparator; a switch side capacitor in parallel with the switch bias set; a ramp side capacitor in parallel with the switch bias set; a ramp generator connected to the comparator via the ramp side capacitor, wherein the ramp generator is configured to generate a ramp signal; a counter; and a memory connected to the comparator, wherein the memory is configured to store an output of the comparator.

In accordance with some embodiments of the present disclosure, an apparatus including a crossbar circuit is provided. The crossbar circuit may include a plurality of cross-point devices with programmable conductance, a transimpedance amplifier (TIA), and an analog-to-digital converter (ADC). The TIA is configured to produce an output voltage based on an input current corresponding to a summation of current from a first plurality of the cross-point devices. The ADC is configured to generate a digital output corresponding to a digital representation of the output voltage of the TIA. To generate the digital output, the ADC is to generate, using a comparator, a first plurality of bits (e.g., MSBs) of the digital output by performing a coarse conversion process and a second plurality of bits (e.g., LSBs) of the digital output by performing a fine conversion process on a sample-and-hold voltage produced in the coarse conversion process.

A multiply-accumulate (MAC) computation circuit includes: a bit-cell array configured to generate an analog output corresponding to a MAC operation result of an input signal; a first analog-to-digital conversion (ADC) circuit configured to determine an upper part of a digital output corresponding to the analog output; and a second ADC circuit configured to determine a lower part of the digital output based on a reference voltage corresponding to the upper part.

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.