An asynchronous successive approximation register analog-to-digital converter (SAR ADC), which utilizes one or more overlapping redundant bits in each digital-to-analog converter (DAC) code word, is operable to generate an indication signal that indicates completion of each comparison step and indicates that an output decision for each comparison step is valid. A timer may be initiated based on the generated indication signal. A timeout signal may be generated that preempts the indication signal and forces a preemptive decision, where the preemptive decision sets one or more remaining bits up to, but not including, the one or more overlapping redundant bits in a corresponding digital-to-analog converter code word for a current comparison step to a particular value. For example, the one or more remaining bits may be set to a value that is derived from a value of a bit that was determined in an immediately preceding decision.

A Successive Approximation Register, SAR, Analog to Digital Converter, ADC, (50) achieves high speed and accuracy by (1) alternating at least some decisions between sets of comparators having different accuracy and noise characteristics, and (2) unevenly allocating redundancy (in the form of LSBs of range) for successive decisions according to the accuracy/noise of the comparator used for the preceding decision. The redundancy allocation is compensated by the addition of decision cycles. Alternating between different comparators removes the comparator reset time (treset) from the critical path, at least for those decision cycles. The uneven allocation of redundancy—specifically, allocating more redundancy to decision cycles immediately following the use of a lower accuracy/higher noise comparators—compensates for the lower accuracy and prevents the need for larger redundancy (relative to the full-scale range of a decision cycle) later in the ADC process.

A computing-in-memory circuit comprises a computing element array and an analog-to-digital conversion circuit. The computing element array is utilized for analog computation operations. The computing element array includes memory cells, a first group of computing elements, and a second group of computing elements. The first group of computing elements provides capacitance for analog computation in response to an input vector and receives data from the plurality of memory cells and the input vector. The second group of computing elements provides capacitance for quantization. Each computing element of the computing element array is based on a switched-capacitors circuit. The analog-to-digital conversion circuit includes a comparator and a conversion control unit. The comparator has a signal terminal, a reference terminal, and a comparison output terminal, wherein the first and second groups of computing elements are selectively coupled to the signal terminal and the reference terminal.

Methods and systems are described for generating a process-voltage-temperature (PVT)-dependent reference voltage at a reference branch circuit based on a reference current obtained via a band gap generator and a common mode voltage input, generating a PVT-dependent output voltage at an output of a static analog calibration circuit responsive to the common mode voltage input and an adjustable current, adjusting the adjustable current through the static analog calibration circuit according to a control signal generated responsive to comparisons of the PVT-dependent output voltage to the PVT-dependent reference voltage, and configuring a clocked data sampler with a PVT-calibrated current by providing the control signal to the clocked data sampler.

Herein disclosed is an example analog-to-digital converter (ADC) and methods that may be performed by the ADC. The ADC may derive a first code that approximates a combination of an analog input value of the ADC and a dither value for the ADC sampled on a capacitor array. The ADC may further derive a second code to represent a residue of the combination with respect to the first code applied to the capacitor array. The ADC may combine the numerical value of the first code and the numerical value of the second code to produce a combined code applied to the capacitor array for deriving a digital output code. Combining the numerical value of the first code and the numerical value of the second code in the digital domain can provide for greater analog-to-digital (A/D) conversion linearity.

In an A/D converter circuit, time required for a first pulse signal to have passed through all first delay units of a first pulse delay circuit is defined as first turnaround time, and time required for a second pulse signal to have passed through all second delay units of a second pulse delay circuit is defined as second turnaround time. Average time required for the first pulse signal to pass through any of the first delay units is defined as first passage time, and average time required for the second pulse signal to pass through any of the second delay units is defined as second passage time. A difference between the first and second passage times enables a difference between the first and second turnaround times to be smaller as compared with a reference difference therebetween for a case where the first and second passage times are identical to each other.

A semiconductor device includes an analog-to-digital converter configured to perform a process of sampling an analog input signal and a successive-approximation process, execute an AD conversion process, and output a digital output signal. The AD converter includes an upper DAC, a redundant DAC, a lower DAC, a comparator configured to compare a comparative reference voltage and output voltages of the upper DAC, the redundant DAC and the lower DAC, a control circuit configured to control successive approximations by the upper DAC, the redundant DAC and the lower DAC based on the comparison result of the comparator, and generate a digital output signal, and a correction circuit. The correction circuit includes an error correction circuit configured to correct an error of the upper bit with the redundant bit, and an averaging circuit configured to calculate an average value of conversion values of a plurality of the lower bits supplied multiple times.

An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.

A Successive Approximation Register, SAR, Analog to Digital Converter, ADC, (50) achieves high speed and accuracy by (1) alternating at least some decisions between sets of comparators having different accuracy and noise characteristics, and (2) unevenly allocating redundancy (in the form of LSBs of range) for successive decisions according to the accuracy/noise of the comparator used for the preceding decision. The redundancy allocation is compensated by the addition of decision cycles. Alternating between different comparators removes the comparator reset time (treset) from the critical path, at least for those decision cycles. The uneven allocation of redundancy—specifically, allocating more redundancy to decision cycles immediately following the use of a lower accuracy/higher noise comparators—compensates for the lower accuracy and prevents the need for larger redundancy (relative to the full-scale range of a decision cycle) later in the ADC process.

An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.