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.

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.

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.

In an embodiment a method for operating a gas sensor arrangement includes generating a sensor current by a gas sensor, converting the sensor current into a digital comparator output signal in a charge balancing operation depending on a first clock signal, determining from the digital comparator output signal an asynchronous count comprising an integer number of counts depending on the first clock signal, determining from the digital comparator output signal a fractional time count depending on a second clock signal and calculating from the asynchronous count and from the fractional time count a digital output signal which is indicative of the sensor current generated by the gas sensor.

In an embodiment a method for operating a gas sensor arrangement includes generating a sensor current by a gas sensor, converting the sensor current into a digital comparator output signal in a charge balancing operation depending on a first clock signal, determining from the digital comparator output signal an asynchronous count comprising an integer number of counts depending on the first clock signal, determining from the digital comparator output signal a fractional time count depending on a second clock signal and calculating from the asynchronous count and from the fractional time count a digital output signal which is indicative of the sensor current generated by the gas sensor.

An optical sensor arrangement comprises a photodiode and a converter arrangement including an integration amplifier, a comparator amplifier, an integration capacitor and a result register. During a precharge phase the result register is set to a starting value. During an integration phase a current is sampled through the photodiode to update the result register in response to down charges applied to an input of the integration amplifier. During a residue phase the result register is updated in dependence on the charge remaining on the integration capacitor. Measuring the residual charge increases resolution and accuracy of the converter.

An optical sensor arrangement comprises a photodiode and a converter arrangement including an integration amplifier, a comparator amplifier, an integration capacitor and a result register. During a precharge phase the result register is set to a starting value. During an integration phase a current is sampled through the photodiode to update the result register in response to down charges applied to an input of the integration amplifier. During a residue phase the result register is updated in dependence on the charge remaining on the integration capacitor. Measuring the residual charge increases resolution and accuracy of the converter.

An analog-to-digital converter, ADC, circuitry, comprises: an integrator connected to a capacitor, the integrator being configured to switch between integrating an analog input signal for ramping an integrator output and integrating a reference input signal for returning integrator output towards a threshold; a comparator for comparing integrator output to the threshold; and a timer for determining a time duration during which the reference input signal is integrated, the time duration providing a digital representation of an analog input signal value; the ADC circuitry further comprising a feedforward noise shaping loop configured to store a quantization error signal based on digitizing a first sample, the comparator being configured to receive a feedforward noise shaping signal for changing the threshold for digitizing a later sample of the analog input signal following the first sample.

Techniques are disclosed for analog-to-digital conversion systems and methods with pulse generators. In one example, an imaging system includes an analog-to-digital converter (ADC). The ADC includes a comparator configured to generate a comparator output signal based on a first signal and a second signal. The comparator output signal is associated with a first state or a second state. The ADC further includes a pulse generator coupled to the comparator. The pulse generator is configured to generate a pulse signal in response to a transition of the comparator output signal from the first state to the second state. The ADC further includes a memory device coupled to the pulse generator. The memory device is configured to capture a counter value from a counter circuit in response to the pulse signal. The counter value is associated with the detector signal. Related methods are also provided.

Techniques are disclosed for analog-to-digital conversion systems and methods with pulse generators. In one example, an imaging system includes an analog-to-digital converter (ADC). The ADC includes a comparator configured to generate a comparator output signal based on a first signal and a second signal. The comparator output signal is associated with a first state or a second state. The ADC further includes a pulse generator coupled to the comparator. The pulse generator is configured to generate a pulse signal in response to a transition of the comparator output signal from the first state to the second state. The ADC further includes a memory device coupled to the pulse generator. The memory device is configured to capture a counter value from a counter circuit in response to the pulse signal. The counter value is associated with the detector signal. Related methods are also provided.