Provided are an analog-to-digital converter and/or an operating method thereof. The analog-to-digital converter includes a sample/hold circuit, a digital-to-analog converter, a comparing circuit, and a control logic circuit, wherein the digital-to-analog converter includes a first capacitor connected to a first comparison node and a first filtering node, a first reference voltage switch connected to the first filtering node and connected to a first delivery node or a first transmission node, a first pre-charge switch connected to the first filtering node or the first delivery node, and a first pre-charge capacitor connected to the first pre-charge switch and a ground voltage.

Analogue-to-digital converter, ADC, circuitry comprising: successive-approximation circuitry configured in a subconversion operation to draw a charge from a first voltage reference, REF1; compensation circuitry comprising at least one compensation capacitor and configured, in a precharge operation prior to the subconversion operation, to connect the at least one compensation capacitor so that the at least one compensation capacitor stores a compensation charge, and, in the subconversion operation, to connect the at least one compensation capacitor to the first voltage reference so that a charge is injected into the first voltage reference, REF1; and control circuitry, wherein: the successive-approximation circuitry and the compensation circuitry are configured such that one or more parameters defining at least one of said charges are controllable; and the control circuitry is configured to adjust at least one said parameter to adjust an extent to which the charge injected into the first voltage reference, REF1, by the compensation circuitry compensates for the charge drawn from the first voltage reference, REF1, by the successive-approximation circuitry.

A sample-and-hold amplification circuit can include a sampling circuit configured to sample first and second input signals in response to first and second control signals to generate first and second sampled signals, an amplification circuit configured to amplify a voltage difference between the first and second sampled signals to generate first and second output signals, and an offset compensation circuit configured to form a first path between input and output terminals of the amplification circuit in response to the first control signal to store an offset of the input terminal and form a second path between the input and output terminals in response to the second control signal to reflect the offset to the output terminal.

The present disclosure discloses a sample and hold amplifier circuit that includes a positive and a negative terminal capacitor arrays, a positive and a negative terminal switch arrays and a differential output circuit. A second terminal of each of bit capacitors in the positive and the negative terminal capacitor arrays are respectively coupled to a positive and a negative output terminal. In a sampling time period, according to a first connection relation, each of the connected bit capacitors is controlled to receive a polarity input voltage to perform a gain modification. In a holding time period, according to a second connection relation, each of the connected bit capacitors is controlled to receive an offset modification voltage to perform an offset modification. A positive and a negative output voltages are generated at the positive and the negative output terminal to be outputted as a pair of differential output signals by the differential output circuit.

An apparatus is disclosed for pipelined analog-to-digital conversion. In an example aspect, the apparatus includes a pipelined analog-to-digital converter (ADC). The pipelined ADC includes a first stage and a second stage. The first stage includes a sampler and a quantizer coupled to the sampler. The first stage also includes a current distribution circuit coupled to the sampler. The second stage includes a sampler coupled to the current distribution circuit and a quantizer coupled to the sampler of the second stage.

An analog-to-digital converter (ADC) is provided. In some examples, the ADC includes a first reference voltage supply input, a second reference voltage supply input, a comparator comprising an input node, and a first reference switch coupled between the second reference voltage supply input and the input node of the comparator. The ADC also includes a set of capacitors, where each capacitor of the set of capacitors comprises a first terminal. In addition, the ADC includes a second reference switch coupled between the first reference voltage supply input and the first terminal of each capacitor of the set of capacitors. The ADC further includes a third switch coupled between the input node of the comparator and the first terminal of each capacitor of the set of capacitors.

Analogue-to-digital converter, ADC, circuitry, including: an analogue input terminal; a comparator having first and second comparator-input terminals; and successive-approximation control circuitry to apply a potential difference across the first and second comparator-input terminals based on an input voltage signal, and to control the potential difference for a series of successive approximation operations to cause the comparator to test in each successive approximation operation whether a magnitude of an analogue input voltage signal is larger or smaller than a corresponding test value, the test value for each successive approximation operation being, dependent on a comparison result generated by the comparator in the preceding approximation operation, bigger or smaller than the test value for the preceding approximation operation by a difference amount configured for that successive approximation operation.

Mixed-signal circuitry including a set of capacitive digital-to-analogue converter, CDAC, units for carrying out digital-to-analogue conversion operations to convert respective digital values into corresponding analogue values; and control circuitry, where: each CDAC unit includes an array of capacitors at least some of which are configured to be individually-switched dependent on the digital values, the capacitors configured to have nominal capacitances; a given capacitor of the array of capacitors in each of the CDAC units is a target capacitor; the set of CDAC units includes a plurality of sub-sets of CDAC units; at least one of the target capacitors per sub-set of CDAC units is a variable capacitor, controllable by the control circuitry to have any one of a plurality of nominal capacitances defined by the configuration of that capacitor.

A mixed-signal in-memory computing sub-cell only requires 9 transistors for 1-bit multiplication. A computing cell is constructed from a plurality of such sub-cells that share a common computing capacitor and a common transistor. Also proposed is a MAC array for performing MAC operations, which includes a plurality of the computing cells each activating the sub-cells therein in a time-multiplexed manner. Also proposed is a differential version of the MAC array with improved computation error tolerance and an in-memory mixed-signal computing module for digitalizing parallel analog outputs of the MAC array and for performing other tasks in the digital domain. An ADC block in the computing module makes full use of capacitors in the MAC array, thus allowing the computing module to have a reduced area and suffer from less computation errors. Also proposed is a method of fully taking advantage of data sparsity to lower the ADC block's power consumption.

A circuit system for weight modulation and image recognition of a memristor array includes a personal computer (PC), a field-programmable gate array (FPGA) chip, a digital-to-analog conversion unit, a switch unit, a memristor array unit, an integration and signal amplification circuit, and an analog-to-digital converter. The circuit system selects a to-be-realized function such as array reading and writing, weight modulation or image recognition, converts a command or an RGB value of an image collected by the PC into a corresponding grayscale value, and sends the grayscale value to the FPGA chip. The FPGA chip controls and selects a to-be-modulated memristor array unit through the digital-to-analog conversion unit and the switch unit. An application program of the PC controls the FPGA chip in real time to realize array reading and writing, weight modulation, and image recognition, and then the FPGA chip displays a result on the PC in real time.