Patent classifications
H03M1/129
Analog-to-digital converter error shaping circuit and successive approximation analog-to-digital converter
Disclosed are an analog-to-digital converter error shaping circuit and a successive approximation analog-to-digital converter. The analog-to-digital converter error shaping circuit includes a decentralized capacitor array, a data weighted average module, a mismatch error shaping module, a control logic generation circuit, a digital filter and a decimator. The decentralized capacitor array includes two symmetrically arranged capacitor array units, each capacitor array unit includes a first sub-capacitor array of a high segment bit and a second sub-capacitor array of a low segment bit. The data weighted average module is configured to eliminate correlation between the first sub-capacitor array and an input signal, and the mismatch error shaping module is configured to eliminate correlation between the second sub-capacitor array and the input signal.
Digital pre-distortion compensation of digital-to-analog converter non-linearity
Systems, apparatuses, and methods for performing digital pre-distortion compensation of digital-to-analog converter non-linearity are described. A correction circuit receives a digital input word and couples a portion of the most significant bits (MSB's) of the digital input word to a correction lookup table (LUT). A correction value is retrieved from a correction LUT entry that matches the MSB's of the digital input word. Next, the correction value is added to the original digital input word in the digital domain. Then, the sum generated by adding the correction value to the original digital input word is optionally clipped if the sum exceeds the DAC core's input range. Next, the DAC core converts the sum into an analog value that is representative of the digital input word. The above approach helps to reduce non-linearities introduced by the DAC core in an energy-efficient manner by performing a correction in the digital domain.
Amplification interface, and corresponding measurement system and method for calibrating an amplification interface
An amplification interface includes first and second differential input terminals, first and second differential output terminals providing first and second output voltages defining a differential output signal, and first and second analog integrators coupled between the first and second differential input terminals and the first and second differential output terminals, the first and second analog integrators being resettable by a reset signal. A control circuit generates the reset signal such that the first and second analog integrators are periodically reset during a reset interval and activated during a measurement interval, receives a control signal indicative of offsets in the measurement sensor current and the reference sensor current, and generates a drive signal as a function of the control signal. First and second current generators coupled first and second compensation circuits to the first and second differential input terminals as a function of a drive signal.
Scalable readout integrated circuit architecture with per-pixel automatic programmable gain for high dynamic range imaging
An imager device includes a pixel sensor configured to receive and convert incident radiation into a pixel signal and a readout circuit configured to receive the pixel signal from the pixel sensor, generate a received signal strength indicator (RSSI) value based on the pixel signal, and generate a digital signal based on the RSSI value and the pixel signal.
Clipped signal pulse restoration after deliberate peak clipping
Saturation of an A/D converter at a receiver is addressed by forcing a controlled clipping of a peak signal pulse in the analog domain and restoring the pulse using a digital algorithm within the receiver. An A/D converter saturates and clips the peak pulses in the signal. Saturated peaks are restored by an algorithm operating in a baseband digital signal processor that utilizes information related to the time intervals where clipping was applied, along with information associated with the portion of the pulse below the clipping threshold. The time interval information is available from the A/D converter or through use of a separate pulse clipping detection algorithm. Through the use of embodiments of the present invention, the effect of signal clipping on receiver performance is reduced and therefore allows for increased clipping of the received signal.
Analog front-end circuit capable of dynamically adjusting gain
An analog front-end circuit capable of dynamically adjusting gain includes a programmable gain amplifier (PGA) circuit, a sensor, a calculation circuit, a gain coarse control circuit and a gain fine control circuit. The PGA circuit includes an amplifier, a gain coarse adjustment circuit and a gain fine adjustment circuit. The gain coarse adjustment circuit is controlled by a coarse control signal, and a gain is adjusted in a coarse step according to an initial gain. The gain fine adjustment circuit is controlled by a fine control signal in a data mode, and the gain is adjusted in a fine step. The calculation circuit calculates a primary gain adjustment and a secondary gain adjustment. The gain coarse control circuit generates the coarse control signal according to the primary gain adjustment, and the gain fine control circuit generates the fine control signal according to the secondary gain adjustment.
Continuous time linear equalization and bandwidth adaptation using asynchronous sampling
Methods and systems are described for generating a time-varying information signal at an output of a continuous time linear equalizer (CTLE), asynchronously sampling a data signal according to a sampling clock having a frequency less than a data rate of the data signal; generating corresponding pattern-verified samples for at least two data patterns, each of the at least two data patterns having a respective frequency content; determining corresponding frequency-specific voltage measurements associated with each of the at least two data patterns based on the corresponding pattern-verified samples of the at least two data patterns; and adjusting an equalization of the data signal based on a comparison of the corresponding frequency-specific voltage measurements.
DIGITAL-TO-ANALOG CONVERTER ARCHITECTURE FOR AUDIO AMPLIFIERS
In some embodiments, a digital-to-analog converter (DAC) architecture can include an array having a total number of bit cells, and a control system configured to activate a selected number of the total number of bit cells and to deactivate the remaining bit cells. The selected number can be variable, such that the array consumes a quiescent current that depends on the selected number. The control system can be further configured to change the selected number when a signal condition exceeds a threshold duration.
DIGITAL-TO-ANALOG CONVERTER CALIBRATION FOR AUDIO AMPLIFIERS
In some embodiments, a calibration circuit can include a first circuit configured to generate a first output voltage based on a first reference voltage, and a second circuit configured to compare the first output voltage and a second reference voltage. The calibration circuit can further include a calibration block configured to provide an adjustment to the first circuit based on the comparison of the first output voltage and the second reference voltage, with the adjustment being configured to compensate for a change in the first reference voltage. In some embodiments, such a calibration circuit can be utilized for and/or be a part of a digital-to-analog converter for wireless audio applications.
Latency Reduction in Analog-to-Digital Converter-Based Receiver Circuits
A serial data receiver circuit included in a computer system may include a front-end circuit, a sample circuit that includes multiple analog-to-digital converter circuits, and a recovery circuit. The front-end circuit may generate an equalized signal using multiple signals that encode a serial data stream of multiple data symbols. Based on a baud rate of the serial data stream, a determined number of the multiple analog-to-digital converter circuits sample, using a recovered clock signal, the equalized signal at the respective times to generate corresponding samples. The recovery circuit generates, using the samples, the recovered clock signal and recovered data symbols.