Circuits and methods for converting digital input signals into the analog domain are described. Such circuits may perform the conversion in a segmented fashion. For example, a circuit may include a most significant bit (MSB) path and a least significant bit (LSB) path. The MSB path may include a first delta-sigma modulator having first and second outputs and a first digital-to-analog converter coupled to the first output of the first delta-sigma modulator. The LSB path comprises a second delta-sigma modulator comprising a loop filter and a quantizer. The quantizer may have an input coupled to the loop filter and to the digital filter. The LSB path may further include a second digital-to-analog converter coupled to an output of the quantizer. The circuit may further include a digital filter and/or a gain stage interposed between the MSB path and the LSB path.

A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.

A modulator of an analog to digital converter includes a quantizer component configured to generate a digital signal based on a clock input operating at a sample rate. The modulator further includes a first digital to analog converter (DAC) configured to generate first DAC output at half the sample rate. The modulator further includes a second DAC configured to generate second DAC output at half the sample rate, where the first DAC and the second DAC are updated at alternate cycles of the clock input.

Switching circuits controllable to force an input into a circuit and to sense a responsively produced output in multiple ways to produce different combinations of positive and negative polarities of a desired signal and of sources of offsets and 1/f noise. The switching circuits are controlled in a non-ordered time sequence of different combinations of positive and negative polarities of the sources of the offsets and 1/f noise that spreads their energy to a frequency range above the desired signal frequency band. The non-ordered time sequence leaves the polarity of the desired signal unchanged. Uncorrelated delta-sigma modulators may generate the control signal. A DSP processes a resulting spectrum of a digital domain version of the sensed output to measure residual offsets and 1/f noise and adds to an input present at the DSMs a signal equal in magnitude and opposite in sign to the measured residual offsets and 1/f noise.

A digital-to-analog conversion device which performs integration processing for integrating a difference between an input signal and a first return signal generated based on the input signal, and outputting an integration result, first quantization processing for quantizing the integration result, and outputting a first quantization signal, first return signal output processing for outputting the first return signal by adding to the first quantization signal a correction value delay signal acquired by a correction value signal outputted based on the integration result being delayed, and output processing for outputting output signals including a signal whose pulse width is asymmetrical to center of a processing period, based on the first quantization signal, in which the correction value signal includes a signal indicating a correction value for correcting a difference between a center of the pulse width asymmetrical to the center of the processing period and the center of the processing period.

A multi-bit continuous-time sigma-delta modulator, SDM, includes an input configured to receive an input analog signal; a first summing junction configured to subtract a feedback analog signal from the input analog signal; a loop filter configured to filter an output signal from the first summing junction: an analog-to-digital converter, ADC, configured to convert the filtered analog output signal to a digital output signal; and a feedback path for routing the digital output signal to the first summing junction. The feedback path includes a plurality of digital-to-analog converters, DACs, configured to convert the digital output signal to an analog form. The ADC includes multiple per-bit parallel loops, each loop configured to provide a per-bit current summation of the filtered analog output signal such that an output of the multiple per-bit parallel loops is a multi-bit quantization digital output signal.

A multi-bit continuous-time sigma-delta modulator, SDM, includes an input configured to receive an input analog signal; a first summing junction configured to subtract a feedback analog signal from the input analog signal; a loop filter configured to filter an output signal from the first summing junction (304): an analog-to-digital converter, ADC, configured to convert the filtered analog output signal to a digital output signal; and a feedback path for routing the digital output signal to the first summing junction. The feedback path includes a plurality of digital-to-analog converters, DACs, configured to convert the digital output signal to an analog form. The ADC comprises a plurality of N-bit comparator latches that are each locally time-interleaved with at least a pair of latches and configured to function in a complementary manner and provide a combined complementary output.

A multi-bit continuous-time sigma-delta modulator, SDM, includes an input configured to receive an input analog signal; a first summing junction configured to subtract a feedback analog signal from the input analog signal; a loop filter configured to filter an output signal from the first summing junction (304): an analog-to-digital converter, ADC, configured to convert the filtered analog output signal to a digital output signal; and a feedback path for routing the digital output signal to the first summing junction. The feedback path includes a plurality of digital-to-analog converters, DACs, configured to convert the digital output signal to an analog form. The ADC comprises a plurality of N-bit comparator latches that are each locally time-interleaved with at least a pair of latches and configured to function in a complementary manner and provide a combined complementary output.

A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.

A method and apparatus for utilizing a wideband radio frequency filter to capture an FM frequency band and configuring the characteristics of a delta-sigma modulator in order to processes desired signals within the FM frequency band. Specifically, the system and method are operative to receive a plurality of FM signals within an FM frequency band, filter the frequency band using a wideband filter, modulating the plurality of FM signals using a delta sigma modulator, down converting and processing the desired signals in parallel.