Abstract: A training signal generator for forming an input signal for an ADC-under-test includes a one-bit DAC and an analog low-pass filter. The one-bit DAC converts a binary sequence into a DAC output signal that is then filtered by the analog low-pass filter to form an ADC input signal. The ADC-under-test converts the ADC input signal into an ADC output signal. A digital low-pass filter converts the binary sequence into a plurality of samples. A digital signal processing system processes the plurality of samples and the ADC output signal to form an estimate of the ADC input signal. An ADC linearizer may then be trained to characterize a non-linear impairment of the ADC-under-test responsive to a comparison of the estimate of the ADC input signal and the ADC output signal.

Abstract: A system includes a switch transistor, and a bootstrap circuit having an input and an output, wherein the output of the bootstrap circuit is coupled to a gate of the switch transistor. The system also includes a first buffer having an input and an output, wherein the output of the first buffer is coupled to a terminal of the switch transistor. The system further includes a second buffer having an input and an output, wherein the input of the second buffer is coupled to the input of the first buffer, and the output of the second buffer is coupled to the input of the bootstrap circuit.

Abstract: Methods and apparatus for noise shaping in multi-stage analog-to-digital converters (ADCs). An example ADC generally includes a first conversion stage having a residue output; an amplifier having an input selectively coupled to the residue output of the first conversion stage; a second conversion stage having an input selectively coupled to an output of the amplifier; and a switched-capacitor network having a first port coupled to the input of the amplifier and having a second port coupled to the input of the second conversion stage, the switched-capacitor network being configured to provide a second-order or higher noise transfer function for noise shaping of quantization noise of the second conversion stage.

Abstract: An apparatus, including a positive input for an input differential signal; a negative input for the input differential signal; a positive output for an output differential signal; a negative output for the output differential signal; a first capacitor including a first terminal coupled to the positive output; a second capacitor including a first terminal coupled to the negative output; and a switching network configured to: couple a second terminal of the first capacitor to the negative input or a positive node based on a mode signal; and couple a second terminal of the second capacitor to the positive input or a negative node based on the mode signal.

Abstract: Certain aspects are directed to an apparatus configured for wireless communication. The apparatus may include a memory comprising instructions, and one or more processors configured to execute the instructions. In some examples, the one or more processors are configured to cause the apparatus to obtain a sample of an analog signal. In some examples, the one or more processors are configured to cause the apparatus to output the sample to an analog-to-digital converter (ADC) via one of at least a first path or a second path based at least in part on whether the sample satisfies a first threshold condition or a second threshold condition.

Abstract: An apparatus is disclosed for gain stabilization. In an example aspect, the apparatus includes an amplifier and a gain-stabilization circuit. The amplifier has a gain that is based on a bias voltage and an amplification control signal. The gain-stabilization circuit is coupled to the amplifier and includes a replica amplifier. The replica amplifier has a replica gain that is based on the bias voltage and the amplification control signal. The gain-stabilization circuit is configured to adjust at least one of the bias voltage or the amplification control signal based on a gain error associated with the replica amplifier.

Abstract: Methods and apparatus for noise shaping in multi-stage analog-to-digital converters (ADCs). An example ADC generally includes a first conversion stage having a residue output; an amplifier having an input selectively coupled to the residue output of the first conversion stage; a second conversion stage having an input selectively coupled to an output of the amplifier; and a switched-capacitor network having a first port coupled to the input of the amplifier and having a second port coupled to the input of the second conversion stage, the switched-capacitor network being configured to provide a second-order or higher noise transfer function for noise shaping of quantization noise of the second conversion stage.

Abstract: Certain aspects are directed to an apparatus configured for wireless communication. The apparatus may include a memory comprising instructions, and one or more processors configured to execute the instructions. In some examples, the one or more processors are configured to cause the apparatus to obtain a sample of an analog signal. In some examples, the one or more processors are configured to cause the apparatus to output the sample to an analog-to-digital converter (ADC) via one of at least a first path or a second path based at least in part on whether the sample satisfies a first threshold condition or a second threshold condition.

Abstract: An apparatus is disclosed for pipelined analog-to-digital conversion. In an example aspect, the apparatus includes a pipelined analog-to-digital converter (ADC). The pipelined ADC includes a first stage and a second stage. The first stage includes a sampler and a quantizer coupled to the sampler. The first stage also includes a current distribution circuit coupled to the sampler. The second stage includes a sampler coupled to the current distribution circuit and a quantizer coupled to the sampler of the second stage.

Abstract: An apparatus is disclosed for pipelined analog-to-digital conversion. In an example aspect, the apparatus includes a pipelined analog-to-digital converter (ADC). The pipelined ADC includes a first stage and a second stage. The first stage includes a sampler and a quantizer coupled to the sampler. The first stage also includes a current distribution circuit coupled to the sampler. The second stage includes a sampler coupled to the current distribution circuit and a quantizer coupled to the sampler of the second stage.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus is disclosed for gain stabilization. In an example aspect, the apparatus includes an amplifier and a gain-stabilization circuit. The amplifier has a gain that is based on a bias voltage and an amplification control signal. The gain- stabilization circuit is coupled to the amplifier and includes a replica amplifier. The replica amplifier has a replica gain that is based on the bias voltage and the amplification control signal. The gain-stabilization circuit is configured to adjust at least one of the bias voltage or the amplification control signal based on a gain error associated with the replica amplifier.

Abstract: A receiver may include a time-interleaved charge sampler comprising a charge sampler switch in series with a charge sampler capacitor. The receiver may also include a current buffer configured to drive the time-interleaved charge sampler.

Abstract: A receiver may include a time-interleaved charge sampler comprising a charge sampler switch in series with a charge sampler capacitor. The receiver may also include a current buffer configured to drive the time-interleaved charge sampler.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for calibrating time-interleaved analog-to-digital converter (ADC) circuits and generating a suitable signal for such calibration. Certain aspects provide a signal generator for calibrating a time-interleaved ADC circuit having a plurality of channels. The signal generator generally includes a pattern generator configured to receive a periodic signal and to output a bitstream based on the periodic signal and a conversion circuit having an input coupled to an output of the pattern generator and configured to generate a waveform based on the bitstream. The bitstream has a bit pattern with a total number of bits that shares no common factor with a number of the channels and includes a relatively lower frequency component combined with a relatively higher frequency component.

Abstract: A continuous-time analog-to-digital converter (ADC) includes a plurality of integrators selectively coupled in series. The ADC may further include a quantizer with excess loop delay (ELD) compensation. The quantizer may be coupled in series to a least one integrator. The ELD compensation may be programmable based on a transfer function of the ADC. The ADC may further include parallel digital-to-analog converters (DACs). Each DAC may have an input coupled to an output of the quantizer, and an output coupled to an input of a corresponding integrator. The ADC may further include a bypass path coupled to an input or output of one of the integrators. The bypass path may be configured to selectively bypass one or more of the integrators to change the transfer function of the ADC.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for implementing sampling rate scaling of an excess loop delay (ELD)-compensated continuous-time delta-sigma modulator (CTDSM) analog-to-digital converter (ADC). One example ADC generally includes a loop filter; a quantizer having an input coupled to an output of the loop filter; one or more digital-to-analog converters (DACs), each having an input coupled to an output of the quantizer, an output coupled to an input of the loop filter, and a data latch comprising a clock input for the DAC coupled to a clock input for the ADC; and a clock delay circuit having an input coupled to the clock input for the ADC and an output coupled to a clock input for the quantizer.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for implementing sampling rate scaling of an excess loop delay (ELD)-compensated continuous-time delta-sigma modulator (CTDSM) analog-to-digital converter (ADC). One example ADC generally includes a loop filter; a quantizer having an input coupled to an output of the loop filter; one or more digital-to-analog converters (DACs), each having an input coupled to an output of the quantizer, an output coupled to an input of the loop filter, and a data latch comprising a clock input for the DAC coupled to a clock input for the ADC; and a clock delay circuit having an input coupled to the clock input for the ADC and an output coupled to a clock input for the quantizer.

Abstract: A method for correcting deterministic jitter in an all-digital phase-locked loop (ADPLL) is described. The method includes determining an offset to an input frequency of the ADPLL that causes an oscillator tuning word (OTW) provided to a digitally-controlled oscillator (DCO) quantizer to fall between two DCO codes. The method also includes applying the offset to the input frequency of the ADPLL to force the DCO quantizer to have gain.