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.

A control circuit and a method of calibrating a signal converter (such as DAC) are disclosed. The control circuit can be an existing control circuit, so no additional calibration circuit is required and the circuit area can be reduced. The control circuit can be an embedded microcontroller or other type of microcontroller. In general, the microcontroller includes an analog comparator and an arithmetic unit. With the combination of using the arithmetic unit to execute firmware program codes and using of the analog comparator, the control circuit is able to calibrate the signal converter.

An integrating Analog-to-digital converter has a global counter that outputs a counter code signal including a multiphase signal. It also has a column circuit including: a ramp wave generation circuit outputting a ramp wave voltage; a comparator comparing the ramp wave voltage with a pixel voltage; and a latch circuit latching the counter code signal at output inversion timing of the comparator. An output value of the latch circuit is used as a digital conversion output value per the column circuit. The counter has a phase division circuit outputting, as an LSB of the digital conversion output value of the integrating analog-to-digital converter, a phase division signal to the latch circuit, the phase division signal dividing a phase of the counter code signal. The phase division circuit is arranged to a plurality of column circuits, and the LSB is shared by a plurality of phase division circuits.

An analog-to-digital converter is provided which is configured to output an n-bit signal in response to an analog input signal. n is greater than 1. The converter comprises n comparators, where each comparator is configured to output one bit of the n-bit signal and comprising a first input and a second input. A first comparator is configured to receive the analog input signal at its first input and a reference value at its second input and to output the first, most significant bit of the n-bit signal. For the remaining comparators, an i-th comparator, is configured to output an i-th bit, the analog-to-digital converter comprises a respective i-th input device. The i-th input device is configured to selectively provide one of 2.sup.i−1 reference values to one of the first or second input of the i-th comparator and the analog input signal to the other one of the first or second input of the i-th comparator, such that the n-bit signal is a Gray code representation of the analog input signal.

The present invention discloses an analog-to-digital conversion circuit having remained time measuring mechanism is provided. A digital-to-analog conversion (DAC) circuit samples input voltages to generate output voltages. A comparator compares the output voltages to generate a comparison result. A control circuit switches a configuration of the DAC circuit by using a digital code according to the comparison result. A comparison determining circuit sets a stage indication signal at a finished state after the comparison result is generated. A comparison stage counting circuit accumulates a termination number according to the stage indication signal to set a conversion indication signal at the finished state when the termination number reaches a predetermined number. A time accumulating circuit starts to accumulate a remained time when the conversion indication signal is at the finished state and finishes accumulation when a sampling indication signal is at a sampling state.

The present disclosure provides a signal conversion circuit and fingerprint identification system. The signal conversion circuit is configured to generate a first digital signal according to a first analog signal, and includes a comparator and counter. The comparator includes a first input terminal configured to receive the first analog signal, a second input terminal connected to a reference voltage generator and configured to receive a reference voltage, and an output terminal configured to output a second digital signal. The counter is connected to the output terminal, and is configured to generate a first digital signal. The signal conversion circuit according to the present disclosure has the advantages of simple circuit structure, small circuit area, low cost and low power consumption.

An image sensor may contain an array of imaging pixels. Each pixel column outputs signals that are read out using a successive approximation register (SAR) analog-to-digital converter (ADC). The SAR ADC may include at least first and second input sampling capacitors, a comparator, a capacitive digital-to-analog converter (CDAC), and associated control circuitry. If desired, the SAR ADC may include a bank of more than two input sampling capacitors alternating between sampling and conversion. The first capacitor may be used to sample an input signal while conversion for the second capacitor is taking place. Prior to conversion, an input voltage of the comparator and an output voltage of the CDAC may be initialized. During conversion of the signal on the first capacitor, the first capacitor is embedded within the SAR ADC feedback loop to prevent charge sharing between the input sampling capacitor and the CDAC, thereby mitigating potential capacitor mismatch issues.

An image sensor may contain an array of imaging pixels. Each pixel column outputs signals that are read out using a successive approximation register (SAR) analog-to-digital converter (ADC). The SAR ADC may include at least first and second input sampling capacitors, a comparator, a capacitive digital-to-analog converter (CDAC), and associated control circuitry. If desired, the SAR ADC may include a bank of more than two input sampling capacitors alternating between sampling and conversion. The first capacitor may be used to sample an input signal while conversion for the second capacitor is taking place. Prior to conversion, an input voltage of the comparator and an output voltage of the CDAC may be initialized. During conversion of the signal on the first capacitor, the first capacitor is embedded within the SAR ADC feedback loop to prevent charge sharing between the input sampling capacitor and the CDAC, thereby mitigating potential capacitor mismatch issues.

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.

A memory device and an operation method thereof are provided. The memory device includes: a memory array including a plurality of memory cells for storing a plurality of weights; a multiplication circuit for performing bitwise multiplication on a plurality of input data and the weights to generate a plurality of multiplication results, wherein in performing bitwise multiplication, the memory cells generate a plurality of memory cell currents; a digital accumulating circuit for performing a digital accumulating on the multiplication results; an analog accumulating circuit for performing an analog accumulating on the memory cell currents to generate a first MAC operation result; and a decision unit for deciding whether to perform the analog accumulating; the digital accumulating or a hybrid accumulating, wherein in performing the hybrid accumulating, whether the digital accumulating circuit is triggered is based on the first MAC operation result.