Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.

Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.

Improved track and hold (T/H) circuits can help analog-to-digital converters (ADCs) achieve higher performance and lower power consumption. The improved T/H circuits can drive high speed and interleaved ADCs, and the design of the circuits enable additive and multiplicative pseudo-random dither signals to be injected in the T/H circuits. The dither signals can be used to calibrate (e.g., linearize) the T/H circuits and the ADC(s). In addition, the dither signal can be used to dither any remaining non-linearity, and to calibrate offset/gain mismatches in interleaved ADCs. The T/H circuit design also can integrate an amplifier in the T/H circuit, which can be used to improve the signal-to-noise ratio (SNR) of the ADC or to act as a variable gain amplifier (VGA) in front of the ADC.

Improved track and hold (T/H) circuits can help analog-to-digital converters (ADCs) achieve higher performance and lower power consumption. The improved T/H circuits can drive high speed and interleaved ADCs, and the design of the circuits enable additive and multiplicative pseudo-random dither signals to be injected in the T/H circuits. The dither signals can be used to calibrate (e.g., linearize) the T/H circuits and the ADC(s). In addition, the dither signal can be used to dither any remaining non-linearity, and to calibrate offset/gain mismatches in interleaved ADCs. The T/H circuit design also can integrate an amplifier in the T/H circuit, which can be used to improve the signal-to-noise ratio (SNR) of the ADC or to act as a variable gain amplifier (VGA) in front of the ADC.

Techniques for saving operating power of an analog-to-digital converter (ADC) are provided. In an example, a circuit can include an ADC configured to provide a multiple-bit digital representation of an analog input during a first mode of operation and an output configured to provide a single bit representation of a first comparison of the analog input signal to a second analog signal during a second mode of operation. In certain examples, the circuit can include an encoder configured to provide the multiple-bit digital representation during the first mode and to power down during the second mode of operation.

An apparatus includes a coarse resolver configured to output coarse position signals indicative of a coarse position of a drive shaft of a motor. The apparatus also includes a fine resolver configured to output fine position signals indicative of a fine position of the drive shaft of the motor. The apparatus further includes a control circuit. The control circuit is configured to receive the coarse position signals from the coarse resolver and the fine position signals from the fine resolver and generate an initial position output, based on the coarse position signals, that indicates an initial position of the drive shaft. The control circuit is further configured to generate a subsequent position output, based on the fine position signals, that indicates a subsequent position of the drive shaft.

Analog-to-digital converter (ADC) circuitry to convert an analog signal to a digital signal is disclosed herein. The ADC circuitry can utilize pipelined-interpolation analog-to-digital converters (PIADCs) with adaptation circuitry to correct regenerative amplification cells of the PIADCs. The PIADCs can implement a rotational shuffling scheme for correction of the regenerative amplification cells, where the correction implemented by the regenerative amplification cells allows for offsetting of latches of the regenerative amplification cells.

Background calibration techniques can effectively to correct for memory, kick-back, and order-dependent errors in interleaved switched-capacitor track-and-hold (T/H) circuits and amplifiers. The techniques calibrate for errors in both the track/sample phase and the hold-phase, and account for the effects of interleaving, buffer/amplifier sharing, incomplete resetting, incomplete settling, chopping, and randomization on the offset, gain, memory, and kick-back errors. Moreover, the techniques can account for order-dependent and state-dependent hold-phase non-linearities. By correcting for these errors, the proposed techniques improve the noise performance, linearity, gain/offset matching, frequency response (and bandwidth), and order-dependence errors. The techniques also help increase the speed (sample rate and bandwidth) and linearity of T/H circuits and amplifiers while simplifying the analog circuitry and clocking needed. These techniques comprehensively account for various memory, kick-back, and order-dependent effects in a unified framework.

A multi-stage analog-to-digital converter includes a signal input terminal, a first stage analog-to-digital converter, a digital-to-analog converter; a second stage analog-to-digital converter, and dither circuitry. The first stage analog-to-digital converter includes an input coupled to the signal input terminal. The digital-to-analog converter includes an input coupled to an output of the first stage analog-to-digital converter, and an input coupled to the signal input terminal. The second stage analog-to-digital converter includes a first input coupled to an output of the digital-to-analog converter. The dither circuitry is coupled to a second input of the second stage analog-to-digital converter, and is configured to provide a dither signal to the second stage analog-to-digital converter during selection of fewer than all bits of a digital value of a residue signal received from the digital-to-analog converter.

A circuit configured to sense an input analog signal generated by a sensor at a first frequency and to generate an output digital signal indicative of the sensed input analog signal. The circuit includes a conditioning circuit, an ADC, a feedback circuit, and a low-pass filter. The conditioning circuit is configured to receive the input analog signal and to generate a conditioned analog signal. The ADC is configured to provide a converted digital signal based on the conditioned analog signal. The feedback circuit includes a band-pass filter configured to selectively detect a periodic signal at a second frequency higher than the first frequency and to act on the conditioning circuit to counter variations of the periodic signal at the second frequency. The low-pass filter is configured to filter out the periodic signal from the converted digital signal to generate the output digital signal.