Abstract: An analog-to-digital (A/D) conversion system includes a track-and-hold circuit, a comparison circuit, a control circuit, a digital-to-analog (D/A) conversion circuit, a switched buffer and a loop filter. The track-and-hold circuit is configured to output a first signal based on an input signal or a first timing signal. The comparison circuit is configured to generate a comparison result based on the first signal and a filtered residue signal. The control circuit is coupled to the comparison circuit, and is configured to generate an N-bit logical signal according to N comparison results from the comparison circuit. The D/A circuit is configured to generate a feedback signal based on the N-bit logical signal. The switched buffer is configured to generate a first error signal based on a second timing signal and a second error signal. The loop filter is configured to generate the filtered residue signal based on the first error signal.

Abstract: An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input signal. A first ADC circuit is coupled to the input terminal and includes a VCO. The first ADC circuit is configured to output a first digital signal in a frequency domain based on the analog input signal. The first digital signal includes an error component. A first DAC is configured to convert the first digital signal to an analog output signal. A first summation circuit is configured to receive the analog output signal, the analog input signal, and a loop filtered version of the analog input signal and extract the error component, and output a negative of the error component. A second ADC circuit is configured to convert the negative of the error component to a digital error signal. A second summation circuit is configured to receive the first digital signal and the digital error signal, and to output a digital output signal corresponding to the analog input at an output terminal.

Abstract: An apparatus and method for analog to digital conversion of analog input signals are disclosed herein. In some embodiments, an analog-to-digital (ADC) may comprise: a first successive approximation register (SAR) circuit comprising a fast SAR (FSAR) circuit and a residue digital-to-analog converter (RDAC) circuit and a residue amplifier circuit, coupled to the RDAC circuit, comprising an amplifier circuit that is configured to amplify a residual signal generated by the RDAC circuit, wherein the amplifier circuit comprises a deadzone control circuit and a first, second and third inverter stages, wherein the third stage is biased to operate in a sub-threshold region.

Abstract: An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.

Abstract: An amplifier includes an input circuit configured to receive an analog input signal and a feedback signal, and output an analog error signal based on the analog input signal and the feedback signal. An ADC is configured to convert the analog error signal into a digital signal in a phase domain. A digital control circuit is configured to generate a digital control signal based on the digital signal in the phase domain. An output circuit is configured to generate an amplified output signal based on the digital control signal, and a feedback circuit is configured generate the feedback signal based on the amplified output signal.

Abstract: An analog-to-digital converter (“ADC”) has an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and an analog residue signal corresponding to a difference between the first digital value and the analog input signal. A second ADC stage is coupled to the first ADC stage and is configured to convert the analog residue signal to a second digital value. At least one of the first ADC stage and the second ADC stage includes a first sub-stage configured to convert an analog signal to a first number of bits of a digital value representing the analog signal, and a second sub-stage configured to convert the analog signal to a second number of bits of the digital value, where the second number of bits is greater than the first number of bits.

Abstract: An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.

Abstract: A class-D amplifier includes an analog-to-digital converter (ADC) configured to generate a first digital signal based on an analog input signal and a feedback signal received at an input node. A loop filter is configured to modify the first digital signal by moving an error of the ADC out of a predetermined frequency band, and a compensation filter is configured to further modify the first digital signal by introducing one or more poles or zeros, thereby generating a second digital signal. An output circuit is configured to generate an output signal at an output node based on the second digital signal, and the feedback signal is generated from the output signal.

Abstract: An analog-to-digital converter (ADC) includes a first ADC stage with a first sub-ADC stage configured to sample the analog input voltage in response to a first phase clock signal and output a first digital value corresponding to an analog input voltage in response to a second phase clock signal. A current steering DAC stage is configured to convert the analog input voltage and the first digital value to respective first and second current signals, determine a residue current signal representing a difference between the first and the second current signal, and convert the residue current signal to an analog residual voltage signal. A second ADC stage is coupled to the first ADC stage to receive the analog residual voltage signal, and convert the analog residue voltage signal to a second digital value. An alignment and digital error correction stage is configured to combine the first and the second digital values.

Abstract: An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input signal. A first ADC circuit is coupled to the input terminal and includes a VCO. The first ADC circuit is configured to output a first digital signal in a frequency domain based on the analog input signal. The first digital signal includes an error component. A first DAC is configured to convert the first digital signal to an analog output signal. A first summation circuit is configured to receive the analog output signal, the analog input signal, and a loop filtered version of the analog input signal and extract the error component, and output a negative of the error component. A second ADC circuit is configured to convert the negative of the error component to a digital error signal. A second summation circuit is configured to receive the first digital signal and the digital error signal, and to output a digital output signal corresponding to the analog input at an output terminal.

Abstract: An analog-to-digital (A/D) conversion system includes a track-and-hold circuit, a comparison circuit, a control circuit, a digital-to-analog (D/A) conversion circuit, a switched buffer and a loop filter. The track-and-hold circuit is configured to output a first signal based on an input signal or a first timing signal. The comparison circuit is configured to generate a comparison result based on the first signal and a filtered residue signal. The control circuit is coupled to the comparison circuit, and is configured to generate an N-bit logical signal according to N comparison results from the comparison circuit. The D/A circuit is configured to generate a feedback signal based on the N-bit logical signal. The switched buffer is configured to generate a first error signal based on a second timing signal and a second error signal. The loop filter is configured to generate the filtered residue signal based on the first error signal.

Abstract: An analog-to-digital converter (ADC) includes a first ADC stage with a first sub-ADC stage configured to output a first digital value corresponding to an analog input voltage. A current steering DAC stage is configured to convert the analog input voltage and the first digital value to respective first and second current signals, determine a residue current signal representing a difference between the first current signal and the second current signal in the current domain, and convert the residue current signal to an analog residual voltage signal. A second ADC stage is coupled to the first ADC stage to receive the analog residual voltage signal, and convert the analog residue voltage signal to a second digital value. An alignment and digital error correction stage is configured to combine the first and the second digital values into a digital output voltage.

Abstract: A circuit includes a voltage-to-time conversion element configured to receive an input voltage at an input and to generate a time domain representation of the input voltage. The voltage-to-time conversion element includes an amplifier having an amplifier input coupled to the input, a zero crossing detector coupled to an output of the amplifier, and a current source selectively coupled to the amplifier input by way of a switching element.

Abstract: An analog-to-digital (A/D) conversion system includes a track-and-hold circuit, a digital-to-analog (D/A) conversion circuit, a comparison circuit and a control circuit. The track-and-hold circuit is configured to output a first signal based on an input signal. The D/A conversion circuit is configured to generate a second signal based on an N-bit logical signal. The comparison circuit is configured to generate a comparison result based on the first signal and the second signal. The control circuit is configured to generate the N-bit logical signal according to N comparison results from the comparison circuit.

Abstract: A class-D amplifier includes an analog-to-digital converter (ADC) configured to generate a first digital signal based on an analog input signal and a feedback signal received at an input node. A loop filter is configured to modify the first digital signal by moving an error of the ADC out of a predetermined frequency band, and a compensation filter is configured to further modify the first digital signal by introducing one or more poles or zeros, thereby generating a second digital signal. An output circuit is configured to generate an output signal at an output node based on the second digital signal, and the feedback signal is generated from the output signal.

Abstract: An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.

Abstract: An analog-to-digital converter (“ADC”) has an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and an analog residue signal corresponding to a difference between the first digital value and the analog input signal. A second ADC stage is coupled to the first ADC stage and is configured to convert the analog residue signal to a second digital value. At least one of the first ADC stage and the second ADC stage includes a first sub-stage configured to convert an analog signal to a first number of bits of a digital value representing the analog signal, and a second sub-stage configured to convert the analog signal to a second number of bits of the digital value, where the second number of bits is greater than the first number of bits.

Abstract: A circuit includes a first integration stage, a quantizer, a second integration stage coupled between the first integration stage and the quantizer, and a digital-to-analog converter (DAC). The first integration stage includes a first input node pair configured to receive a pair of differential analog input signals, and the quantizer is configured to generate a digital signal based on the pair of differential analog input signals and a clock signal. The second integration stage includes a second input node pair, and the DAC is configured to receive the digital signal and output feedback signals to at least one input node pair of the first input node pair or the second input node pair.

Abstract: An analog-to-digital converter (“ADC”) has an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and an analog residue signal corresponding to a difference between the first digital value and the analog input signal. A second ADC stage is coupled to the first ADC stage and is configured to convert the analog residue signal to a second digital value. At least one of the first ADC stage and the second ADC stage includes a first sub-stage configured to convert an analog signal to a first number of bits of a digital value representing the analog signal, and a second sub-stage configured to convert the analog signal to a second number of bits of the digital value, where the second number of bits is greater than the first number of bits.

Abstract: An analog-to-digital converter (ADC) is disclosed. The ADC includes a successive approximation register and a voltage-to-time conversion element. The successive approximation register is configured to receive an input signal and to generate a first digital signal and a residue voltage. The voltage-to-time conversion element is configured to convert the residue voltage to a time domain representation. The voltage-to-time conversion element includes an amplifier having an input coupled to an output of the successive approximation register and configured to receive the residue voltage, and a zero crossing detector directly coupled to an output of the amplifier. A time-to-digital converter is coupled to an output of the zero crossing detector and is configured to generate a second digital signal.