A continuous-time sigma-delta modulator includes a VCO-based quantizer, a rotator, a truncation circuit and a digital-to-analog converter (DAC). The VCO-based quantizer is arranged to generate a thermometer code based on an input signal and a feedback signal. The rotator is coupled to the VCO-based quantizer, and is arranged to generate a phase-shifted thermometer code based on the thermometer code and a phase shift, and generate a rearranged thermometer code based on the phase-shifted thermometer code to comply with a specific pattern. The truncation circuit is coupled to the rotator, and is arranged to extract a most significant bit (MSB) part from the rearranged thermometer code. The DAC is coupled to the truncation circuit, and is arranged to generate the feedback signal according to at least the MSB part. Two alternative continuous-time sigma-delta modulators are also disclosed.

A system may include a delta-sigma analog-to-digital converter and a digital compression circuit. The delta-sigma analog-to-digital converter may include a loop filter having a loop filter input configured to receive an input signal and generate an intermediate signal responsive to the input signal, a multi-bit quantizer configured to quantize the intermediate signal into an uncompressed digital output signal, and a feedback digital-to-analog converter having a feedback output configured to generate a feedback output signal responsive to the uncompressed digital output signal in order to combine the input signal and the feedback output signal at the loop filter input. The digital compression circuit may be configured to receive the uncompressed digital output signal and compress the uncompressed digital output signal into a compressed digital output signal having fewer quantization levels than that of the uncompressed digital output signal.

An oversampling analog-to-digital converter (ADC) may include a quantizer that adds an offset error to each oversampling sample. If not reduced, the offset error may limit the performance of the ADC. The existing methods to eliminate the offset may increase a circuit size and slow the operation of the ADC. An oversampling ADC that can reduce, or remove, the offset error is disclosed. The disclosed ADC can be small and fast and still remove the offset. Accordingly, the disclosed ADC may be used in high performance applications, such as a high-speed image sensor.

It is described a voltage regulator device (100), comprising: i) a power device (150), configured to receive an input signal (151) and to produce a corresponding output signal (152); ii) a comparator device (110), coupled via a feedback path (140) to the power device (150), and configured to receive the output signal (152) as a feedback signal (141), and to produce a compared feedback signal (112); and iii) a digital modulation device (120), arranged between the comparator device (110) and the power device (150), and configured to digitally modulate the compared feedback signal (112), and to provide the digitally modulated signal (121) to the power device (150), wherein the digital modulation device (120) comprises: iiia) a delta-sigma (122), iiib) a quantizer (124), and iiic) a feedforward path (128), configured to feedforward the compared feedback signal (112) beyond the delta-sigma (122).

An oversampling analog-to-digital converter (ADC) may include a quantizer that adds an offset error to each oversampling sample. If not reduced, the offset error may limit the performance of the ADC. The existing methods to eliminate the offset may increase a circuit size and slow the operation of the ADC. An oversampling ADC that can reduce, or remove, the offset error is disclosed. The disclosed ADC can be small and fast and still remove the offset. Accordingly, the disclosed ADC may be used in high performance applications, such as a high-speed image sensor.