An amplifier circuit includes a resistor divider (R.sub.REF) comprising n resistive elements, two main nodes defined at each end thereof, two readout nodes (d.sub.1, d.sub.2), resistor nodes (q) defined between adjacent resistive elements, and an input current source (I.sub.REF) connected or connectable to the first main node (a). The resistor divider (R.sub.REF) comprises two arrays of addressable switch elements controllable by a feedback signal (s.sub.FB) to be open or closed. The amplifier circuit includes a differential pair of transistors (T.sub.1, T.sub.2), wherein source terminals of each of the transistors (T.sub.1, T.sub.2) are connected to the second node (b), gate terminals of the transistors (T.sub.1, T.sub.2) are connected to input signals (v.sub.1, v.sub.2), drain terminals of the transistors (T.sub.1, T.sub.2) are connected to current sources (I.sub.1, I.sub.2), and bulk terminals of the transistors (T.sub.1, T.sub.2) are connected to the readout nodes (d.sub.1, d.sub.2). The amplifier circuit functions as a difference amplifier, wherein the bulk terminals affect a threshold of the respective transistors (T.sub.1, T.sub.2) so as to add or subtract a differential signal derived from the readout nodes (d.sub.1, d.sub.2) of the resistor divider (R.sub.REF) determined by the feedback signal (s.sub.FB).

An analog-to-digital converter (ADC) is based on single-bit delta-sigma quantization. The ADC includes an integrator, a threshold detector, a feedback block, a range control circuit and an output processing block. The ADC is configured to, based on its own generated digital bitstream, adjust the magnitude of a subtrahend signal in order to achieve autonomous auto-ranging of the ADC during the integration time of a measurement. In particular, the auto-ranging allows for the efficient conversion of an analog input signal with high dynamic range, for example ambient light, to a digital output signal.

This application relates to analogue-to-digital converters (ADCs). An ADC 200 has a first converter (201) for receiving an analogue input signal (AIN) and outputting a time encode signal (DT), such as a pulse-width-modulated (PWM) signal, based on input signal and a first conversion gain setting (GIN). In some embodiments the first converter has a PWM modulator (401) for generating a PWM signal such that the input signal is encoded by pulse widths that can vary continuously in time. A second converter (202) receives the time encoded signal and outputs a digital output signal (DOUT) based on the time encoded signal (DT) and a second conversion gain setting (GO). The second converter may have a first PWM-to-digital modulator (403). A gain allocation block (204) generates the first and second conversion gain settings based on the time encoded signal (DT). The gain allocation block (204) may have a second PWM-to-digital modulator (203) which may be of lower latency and/or lower resolution that the first PWM-to-digital modulator (403).

An image sensor includes a pixel array, a controller, and a plurality of analog-to-digital converters. The pixel array includes a plurality of pixels coupled to column lines, respectively, and the plurality of pixels are configured to sense incident lights to generate analog signals through the column lines. The controller generate a conversion control signal that is configurable based on changes of at least one operational condition. The plurality of analog-to-digital converters are coupled to the column lines, respectively. The plurality of analog-to-digital converters perform a delta-sigma modulation and a digital filtering to convert the analog signals to digital signals. The plurality of analog-to-digital converters adjust a conversion gain internally in response to the conversion control signal.

Disclosed are a continuous-time delta-sigma analog-to-digital converter and an operation method thereof. More particularly, a continuous-time delta-sigma analog-to-digital converter, including: a linear integrator configured to generate a first output signal corresponding to a preset input voltage based on an operation of a linear Gm circuit that receives the preset input voltage; and a quantizer configured to generate a second output signal corresponding to the first output signal based on an operation of a body-driven VCO that receives the first output signal and to generate a digital output code corresponding to the second output signal based on an operation of a Frequency to Digital Converter (FDC) that receives the second output signal is disclosed.

A PWM modulator has a quantizer that generates a PWM output signal to speaker driver. When a first voltage swing range is supplied to the speaker driver, the quantizer analog gain is controlled to be a first gain value. When a second PWM drive voltage swing range is supplied to the speaker driver, the analog gain is controlled to be a second gain value. The first and second gain values of the analog gain of the quantizer cause the combined gain of the quantizer and driver to be approximately equal in the two modes. The quantizer has at least two gain-affecting measurable non-ideal characteristics. The quantizer is adjustable using measured first and second values to correct for first and second of the at least two non-ideal characteristics. The gain of the quantizer is calibratable while the quantizer is adjusted using the measured first and second measured values.

The invention relates to an analog-to-digital converter, ADC, based on single-bit delta-sigma quantization. The ADC includes an integrator, a threshold detector, a feedback block, a range control circuit and an output processing block. The ADC is configured to, based on its own generated digital bitstream, adjust the magnitude of a subtrahend signal in order to achieve autonomous auto-ranging of the ADC during the integration time of a measurement. In particular, the auto-ranging allows for the efficient conversion of an analog input signal with high dynamic range, for example ambient light, to a digital output signal.

A PWM modulator has a quantizer that generates a PWM output signal to speaker driver. When a first voltage swing range is supplied to the speaker driver, the quantizer analog gain is controlled to be a first gain value. When a second PWM drive voltage swing range is supplied to the speaker driver, the analog gain is controlled to be a second gain value. The first and second gain values of the analog gain of the quantizer cause the combined gain of the quantizer and driver to be approximately equal in the two modes. The quantizer has at least two gain-affecting measurable non-ideal characteristics. The quantizer is adjustable using measured first and second values to correct for first and second of the at least two non-ideal characteristics. The gain of the quantizer is calibratable while the quantizer is adjusted using the measured first and second measured values.

A sigma-delta analog-to-digital converter including a gain element connected to an integrator. The gain element switches between different gain values during consecutive phases of a clock signal having a different number of clock cycles. A counter is configured to count with a different increment step size dependent on the first and second gain values. The converter may be part of a sensor arrangement with a temperature sensor.

An apparatus for dynamic range enhancement (DRE) which receives an input signal and provides a DRE output signal is presented. The apparatus has an error correction circuit to apply an error correction factor to the input signal such that the DRE output signal provided by the apparatus is dependent on the input signal and the error correction factor. The error correction factor is representative of an error generated by the apparatus.