A digital phase-locked loop (DPLL) may include a time-to-digital converter (TDC) to provide a phase error signal, a frequency-divider to perform frequency division on an output signal to generate a frequency-divided output signal, a delta-sigma-modulator (DSM) to provide a test signal that represents a quantization error of the DSM, and a digital-to-time converter (DTC) to at least partially remove the quantization error from the frequency-divided output signal based on the test signal to generate the feedback signal. The DPLL may include a circuit to cause the DTC to provide a percentage of the quantization error such that the percentage of the quantization error is in the phase error signal, and a TDC calibration component to calibrate the TDC by applying a gain adjustment factor to the TDC. The gain adjustment factor may be based on the test signal and the phase error signal including the percentage of the quantization error.

An apparatus is disclosed for analog-to-digital conversion. In an example aspect, the apparatus includes an analog-to-digital converter (ADC). The ADC includes a reference-crossing detector having an input and an output. The ADC also includes a ramp generator coupled between the output of the reference-crossing detector and the input of the reference-crossing detector. The ADC further includes a voltage shifter coupled between the output of the reference-crossing detector and the input of the reference-crossing detector.

The present disclosure relates to communication devices and provides a method and apparatus for calibrating a sampling timing skew between time-interleaved analog to digital converter (ADC) channels, a time-interleaved ADC, an electronic device, and a computer readable medium. The time-interleaved ADC includes multiple ADC channels. The method includes: calculating, for every two adjacent channels, a correlation value between digital signals of two adjacent channels, according to the digital signals output by every two adjacent channels; calculating a timing skew adjustment amount corresponding to a sampling timing skew of each of the channels relative to a reference channel according to the correlation value corresponding to every two adjacent channels, the reference channel being any designated channel among the plurality of channels; and calibrating the sampling timing skew of each of the channels relative to the reference channel according to the timing skew adjustment amount corresponding to each of the channels.

A calibration system comprises an actuator circuit comprising a first delay circuit that receives a plurality of data pulses and a second delay circuit that receives the pulses, wherein one of the first and second delay circuits delays the data pulses independently of the other of the first and second delay circuits; a data switch that receives an output of the actuator circuit including delay data signals of the data pulses from the first and second delay circuits and switches and outputs a plurality of local oscillator (LO) signals for output as a controlled LO signal according to control signals of the delay data signals and applied to the data switch. At least one calibration switch receives the output of the actuator circuit and the plurality of LO+ and LO− signals, and outputs a second controlled LO signal output to a sense circuit.

A method of operating a pipelined analog-to-digital converter (ADC) having a plurality of output stages includes: performing a first calibration process for the pipelined ADC to update a parameter vector of the pipelined ADC, where components of the parameter vector are used for correcting nonlinearity of the pipelined ADC, where performing the first calibration process includes: providing an input signal to the pipelined ADC; converting, by the pipelined ADC, the input signal into a first digital output; providing a scaled version of the input signal to the pipelined ADC, where the scaled version of the input signal is generated by scaling the input signal by a scale factor; converting, by the pipelined ADC, the scaled version of the input signal into a second digital output; and calibrating the pipelined ADC using the first digital output and the second digital output.

A clock product includes a time-to-digital converter responsive to an input clock signal, a reference clock signal, and a time-to-digital converter calibration signal. The time-to-digital converter includes a coarse time-to-digital converter and a fine time-to digital converter. The clock product includes a calibration circuit including a phase-locked loop. The calibration circuit is configured to generate the time-to-digital converter calibration signal. The clock product includes a controller configured to execute instructions that cause the phase-locked loop to generate an error signal for each possible value of a fine time code of a digital time code generated by the time-to-digital converter and to average the error signal over multiple clock cycles to generate an average error signal.

In a method of operating an analog-to-digital converter, a gain error and an offset error that are associated with a digital code generated from the analog-to-digital converter are obtained by performing a first analog-to-digital conversion on a first input analog signal. The gain error and the offset error are stored. A calibration digital code is generated by performing a second analog-to-digital conversion on a second input analog signal based on the gain error and the offset error.

An interleaved analog-to-digital conversion (ADC) system may have timing errors in a time domain that is corrected using phase compensation in a phase domain. The ADC system may include sub-ADCs, each receiving a clock signal, which is associated with a representation of a timing skew value, reflecting an undesired timing error. A mixer may have sub-mixers, each receiving a sub-ADC output signal and a compensated numerically controlled oscillator (NCO) value. A combiner may combine the sub-mixer output signals. A decimator may decimate the output of the combiner. Each timing skew value is in a time domain. A compensated NCO value is determined using a respective phase skew value. Each phase skew value is an offset value in phase and is not a value in time. Each phase skew value in a phase domain compensates the respective timing skew value in a time domain. Multiple ADC systems and methods are described.

A system and method for equalization of a linear or non-linear system. The system includes an adder configured to add an analog reference signal and an input signal, a processing system configured to process a sum of the analog reference signal and the input signal, a non-linear equalizer (NLEQ) configured to process an output of the processing system to remove a distortion incurred by the processing system, a calibration circuitry configured to generate a reconstructed reference signal in digital domain based on measurement of the analog reference signal, and generate coefficients for the NLEQ based on the reconstructed reference signal and the output of the processing system, and a subtractor configured to subtract the reconstructed reference signal from an output of the NLEQ. The analog reference signal may be a sinusoid including single or multiple tones of sinusoids. The non-linear system may be an analog-to-digital converter (ADC).

In one aspect, an integrated circuit (IC) includes a magnetic-field sensor. The magnetic-field sensor includes digital circuitry that includes a first and second analog-to-digital converter (ADC). The digital circuitry is configured to receive a first and second analog output signals and, using the first and second ADC, configured to convert the first and second analog output signals to a first and second digital signals. The magnetic-field sensor also includes diagnostic circuitry configured to receive, from the digital circuitry, an input signal related to the first and/or the second digital signals and configured to provide a test signal at a pin of the IC. In response to a range parameter, the diagnostic circuitry is further configured to provide the test signal comprising a range of codes from the first and/or the second ADC corresponding to the range parameter.