A sensor arrangement for light sensing for light-to-frequency conversion. The sensor arrangement includes a photodiode, an analog-to-digital converter (ADC) operable to perform a chopping technique in response to a first clock signal (CLK1), and convert a photocurrent (IPD) into a digital comparator output signal (LOUT). The ADC includes a sensor input coupled to the photodiode, an output for providing the digital comparator output signal (LOUT), an integrator including an integrator input coupled to the sensor input and operable to receive an integrator input signal, a first set of chopping switches coupled to a first amplifier, a second set of chopping switches electrically coupled to an output of the first amplifier and electrically coupled to input terminals of a second amplifier, and an integrator output providing an integrator output signal (OPOUT).

A sensor arrangement for light sensing for light-to-frequency conversion. The sensor arrangement includes a photodiode, an analog-to-digital converter (ADC) operable to perform a chopping technique in response to a first clock signal (CLK1), and convert a photocurrent (IPD) into a digital comparator output signal (LOUT). The ADC includes a sensor input coupled to the photodiode, an output for providing the digital comparator output signal (LOUT), an integrator including an integrator input coupled to the sensor input and operable to receive an integrator input signal, a first set of chopping switches coupled to a first amplifier, a second set of chopping switches electrically coupled to an output of the first amplifier and electrically coupled to input terminals of a second amplifier, and an integrator output providing an integrator output signal (OPOUT).

The disclosure is directed to low-power high-resolution analog-to-digital converter (ADCs) circuits implemented with a delta-sigma modulators (DSMs). The DSM includes a single-bit, self-oscillating digital to analog converter (SB-DAC) and a dual-slope integrating quantizer that may replace an N-bit quantizer found in a conventional DSM. The integrating quantizer of this disclosure oscillates after quantization because the SB-DAC in the feedback path directly closes the DSM loop. The integrating quantizer circuit includes a switch at the input and two phases per sample cycle. During the first phase the switch sends an input analog signal to an integrator. During the second phase, the switch sends the feedback signal from the output of the self-oscillating SB-DAC to the integrator. The input to the SB-DAC may be output from a clocked comparator.

A charge rebalancing integration circuit can help keep an output node of a front-end integration circuit within a specified range, e.g., without requiring resetting of the integration capacitor. The process of monitoring and rebalancing the integration circuit can operate on a much shorter time base than the integration time period, which can allow for multiple charge balancing charge transfer events during the integration time period, and sampling of the integration capacitor once per integration time period, such as at the end of that integration time period. Information about the charge rebalancing can be used to adjust subsequent discrete-time signal processing, such as digitized values of the samples. Improved dynamic range and noise performance is possible. Computed tomography (CT) imaging and other use cases are described, including those with variable integration periods.

An AD converter is provided with a control unit including a calibration control unit that controls an operation for calibrating the control unit and a conversion control unit that controls an operation for converting a target input voltage into a digital signal; a reference voltage unit that outputs a reference voltage; and an integrating converter unit including an integrating unit that generates an integrated voltage by integrating a predetermined unit voltage, a comparator that has two inputs and compares the integrated voltage and an input voltage or a reference voltage Vref, and a crossbar switch that switches connections between the case where the integrated voltage is inputted to one of the inputs of the comparator and the input voltage or the reference voltage Vref is inputted to the other input and the case where the input voltage or the reference voltage Vref is inputted to one of the inputs of the comparator and the integrated voltage is inputted to the other input.

An analog-to-digital converter includes a voltage-controlled oscillator (VCO) having an input for receiving an analog input signal; a double binary counter having a first input coupled to a first output of the VCO, a second input coupled to a second output of the VCO; a first set of registers coupled to the first output of the double binary counter; a second set of registers coupled to the second output of the double binary counter; sense amplifiers coupled to the outputs of the VCO; and a correction component coupled to the first set of registers, the second set of registers, and the sense amplifiers, wherein the correction component generates a coarse count, a fine count, and combines the coarse count and the fine count to provide a digital output signal representative of the analog input signal.

There is provided a dual-slope analog-to-digital converter (ADC), comprising an input signal terminal, configured to provide an analog signal, and a reference signal terminal, configured to provide a predetermined reference signal. The ADC further comprises an integrator, that is operatively coupled to said input signal terminal and said reference signal terminal via a first switch unit, said first switch unit being configured to selectively connect and disconnect said integrator to and from any one of said input signal terminal and said reference signal terminal. In addition, a voltage supply is operatively coupled to said integrator and configured to selectively provide at least one first supply voltage to said integrator via a second switch unit, a comparator is operatively coupled to an output of said integrator at a first comparator input and a predetermined threshold voltage at a second comparator input, configured to provide an actuation signal at a comparator output in accordance with a predetermined comparator logic, and a controller is adapted to control any one of said first switch unit and said second switch unit. The ADC is further adapted to provide a first voltage to said integrator from said voltage supply, so as to integrate over a first time period a first current corresponding to one of said reference signal and said analog signal, and, following said first time period, to provide a second voltage to said integrator from said voltage supply, so as to integrate over a second time period a second current corresponding to the other one of said reference signal and said analog signal, in order to generate a digital output signal corresponding to said analog signal, and wherein said first current and said second current flow in the same direction during respective said first time period and said second time period.

An integrated circuit includes an analog-to-digital converter (ADC) configured to receive input voltage, and first and second reference voltages, and outputs digital code representing ratios between the input voltage and the first and the second reference voltages. The first and second reference voltages are generated by a reference generator using different current densities. During a first stage, the ADC samples the first input voltage and the first reference voltage and transfers equivalent charge of the sampled first input voltage and first reference voltage to an integration capacitor. During a second stage, the ADC samples the second reference voltage and transfers equivalent charge of the sampled second reference voltage to the integration capacitor. The ADC provides one bit of digital code based on total charge stored on the integration capacitor after the transfers of charge of the sampled input voltage, and the sampled first and second reference voltages.

A sensor arrangement for light sensing for light-to-frequency conversion. The sensor arrangement includes a photodiode, an analog-to-digital converter (ADC) operable to perform a chopping technique in response to a first clock signal (CLK1), and convert a photocurrent (IPD) into a digital comparator output signal (LOUT). The ADC includes a sensor input coupled to the photodiode, an output for providing the digital comparator output signal (LOUT), an integrator including an integrator input coupled to the sensor input and operable to receive an integrator input signal, a first set of chopping switches coupled to a first amplifier, a second set of chopping switches electrically coupled to an output of the first amplifier and electrically coupled to input terminals of a second amplifier, and an integrator output providing an integrator output signal (OPOUT).

A sensor arrangement for light sensing for light-to-frequency conversion. The sensor arrangement includes a photodiode, an analog-to-digital converter (ADC) operable to perform a chopping technique in response to a first clock signal (CLK1), and convert a photocurrent (IPD) into a digital comparator output signal (LOUT). The ADC includes a sensor input coupled to the photodiode, an output for providing the digital comparator output signal (LOUT), an integrator including an integrator input coupled to the sensor input and operable to receive an integrator input signal, a first set of chopping switches coupled to a first amplifier, a second set of chopping switches electrically coupled to an output of the first amplifier and electrically coupled to input terminals of a second amplifier, and an integrator output providing an integrator output signal (OPOUT).