One example discloses a reconfigurable analog to digital converter (ADC) device, including: an analog front end (AFE) configured to receive a set of analog input signals and generate a corresponding set of digital output signals; wherein the AFE includes a set of reconfigurable ADC conversion circuits; and a sequencer coupled to the AFE and configured to control the set of reconfigurable ADC conversion circuits with a first AFE channel configuration at a first time and a second AFE channel configuration at a second time.

A MASH type sigma delta AD converter includes a modulator, an analog filter filtering an extraction signal obtained by extracting a probe signal and an quantization error generated in a quantizer within a sigma delta modulator, a low speed AD converter performing an AD conversion of an output signal of the analog filter, a first adaptive filter searching for a transfer function of the sigma delta modulator, a second adaptive filter searching for a transfer function from an output of the modulator to the low speed AD converter via the analog filter, and a noise cancellation circuit cancelling the probe signal and the quantization error included in an output signal of the quantizer using the search results by the first and second adaptive filters.

A N-bit continuous-time sigma-delta modulator, SDM, (800) includes an input configured to receive an input analog signal (302); a first summing junction (304) configured to subtract a feedback analog signal (303) from the input analog signal (302); a loop filter (306) configured to filter an output signal from the first summing junction (304): an N-bit analog-to-digital converter, ADC, comprising at least one 1-bit ADC configured to convert the filtered analog output signal (309) to a digital output signal (314) where each 1-bit ADC comprises at least one pair of comparator latches (336, 356); and a feedback path (316) for routing the digital output signal to the first summing junction (304). The feedback path (316) includes a plurality of digital-to-analog converters, DACs, configured to convert the digital output signal (314) to an analog form. The ADC comprises or is operably coupled to, a calibration circuit (650, 840) coupled to an input and an output of the at least one pair of comparator latches (336, 356) and configured to apply respective calibration signals to individual comparator latches of the at least one pair of comparator latches (336, 356) in a time-Interleaved manner, and calibrate a comparator error of the comparator latches in response to a latched output of the respective calibration signals.

An open-loop digital-to-analog converter (DAC) circuit may include a delta-sigma modulator, a decode block responsive to the delta-sigma modulator configured to perform a DAC decode operation, a plurality of DAC elements responsive to the DAC decode operation, an analog output driver responsive to the plurality of DAC elements, a test signal generator configured to generate a test signal that is responsive to inputs of the plurality of DAC elements, and a synchronizer configured to enable replication of the test signal at an external test system coupled to the open-loop DAC circuit in order to generate a matching test signal at the external test system that matches the test signal generated by the test signal generator.

A DAC error measurement apparatus includes: an ADC and a feedback DAC, where a measurement input of the ADC includes a square wave signal with a constant frequency, a direct-current signal at a constant logical level, and an analog output of the feedback DAC; a measurement selection module, configured to provide a measured digit in a digital output to a separately selected source cell, and provide remaining digits in the digital output to remaining source cells, where the measured digit is a flippable digit, and the remaining digits are non-flipping digits; and a measurement module, configured to measure an amplitude of the digital output based on the digital output. One flipping digit in the digital output is the measured digit, and the remaining digits are the non-flipping digits, such that the measurement selection module may separately select one source cell to receive the measured digit.

An open-loop digital-to-analog converter (DAC) circuit may include a delta-sigma modulator, a decode block responsive to the delta-sigma modulator configured to perform a DAC decode operation, a plurality of DAC elements responsive to the DAC decode operation, an analog output driver responsive to the plurality of DAC elements, a test signal generator configured to generate a test signal that is responsive to inputs of the plurality of DAC elements, and a synchronizer configured to enable replication of the test signal at an external test system coupled to the open-loop DAC circuit in order to generate a matching test signal at the external test system that matches the test signal generated by the test signal generator.

A N-bit continuous-time sigma-delta modulator, SDM, (800) includes an input configured to receive an input analog signal (302); a first summing junction (304) configured to subtract a feedback analog signal (303) from the input analog signal (302); a loop filter (306) configured to filter an output signal from the first summing junction (304): an N-bit analog-to-digital converter, ADC, comprising at least one 1-bit ADC configured to convert the filtered analog output signal (309) to a digital output signal (314) where each 1-bit ADC comprises at least one pair of comparator latches (336, 356); and a feedback path (316) for routing the digital output signal to the first summing junction (304). The feedback path (316) includes a plurality of digital-to-analog converters, DACs, configured to convert the digital output signal (314) to an analog form. The ADC comprises or is operably coupled to, a calibration circuit (650, 840) coupled to an input and an output of the at least one pair of comparator latches (336, 356) and configured to apply respective calibration signals to individual comparator latches of the at least one pair of comparator latches (336, 356) in a time-Interleaved manner, and calibrate a comparator error of the comparator latches in response to a latched output of the respective calibration signals.

A method for non-linearity correction includes receiving a first output signal from a data signal path containing a first analog-to-digital converter and receiving a second output signal from a second analog-to-digital converter. The method also includes generating first non-linearity coefficients using the first output signal and generating second non-linearity coefficients using the first and second output signals. The method further includes applying, by a non-linearity corrector in the data signal path, the first and second non-linearity coefficients to compensate for non-linearity components in a digitized signal output from the first analog-to-digital converter to generate a corrected digitized signal.

Disclosed examples include a segmented DAC circuit, including an R-2R resistor DAC to convert a first subword to a first analog output signal, an interpolation DAC to offset the first analog output signal based on an N-bit digital interpolation code signal to provide the analog output signal, and a Sigma Delta modulator to modulate a modulator code to provide the N-bit digital interpolation code signal that represents a value of second and third subwords.

A semiconductor apparatus is used together with a processor. An A/D converter is configured to be calibratable. A logic circuit periodically supplies a calibration trigger to the A/D converter by means of a count operation using the output of an oscillator.