Patent classifications
H03M1/1033
MULTIPLYING DIGITAL-TO-ANALOG CONVERTER (MDAC) WITH NONLINEAR CALIBRATION
A system includes a multiplying digital-to-analog converter (MDAC). The system also includes an input-side component coupled to the MDAC and configured to provide a code to the MDAC. The system also includes a reference voltage source coupled to the MDAC and configured to provide a reference voltage to the MDAC. The MDAC comprises a nonlinear calibration circuit configured to adjust an output of the MDAC nonlinearly based on the code, the reference voltage, and an output of the nonlinear calibration circuit.
LINEAR CALIBRATION SYSTEM AND METHOD FOR TIME-TO-DIGITAL CONVERTER AND DIGITAL PHASE-LOCKED LOOP
The present disclosure provides a linear calibration system for a time-to-digital converter and a method thereof, and a digital phase-locked loop. The linear calibration system includes a digitally controlled reference delay circuit for receiving a first clock signal and delaying the first clock signal to generate a reference clock signal, a time-to-digital conversion circuit including at least two time-to-digital converters, and a state machine. The time-to-digital conversion circuit receives the first clock signal and the reference clock signal, delays the first clock signal to generate a first delay signal, compares a phase of the first delay signal with a phase of the reference clock signal, and outputs a phase detection result signal. The state machine generates a delay control signal for controlling the digitally controlled reference delay circuit, adjusts a calibration control signal to align the phases of the first delay signal and the reference clock signal.
Delay compensated single slope analog-to-digital converter
Various embodiments relate to a single slope analog to digital converter (ADC), including: a voltage slope generator; a reference voltage generator configured to generate a first reference voltage, a second reference voltage, and a third reference voltage, where the first reference voltage equals the sum of the second reference voltage and the third reference voltage; a first comparator configured to compare a voltage to a voltage output from the voltage slope generator; a first register configured to store a first count based upon the first reference voltage being input into the first comparator; a second register configured to store a second count based upon the second reference voltage being input into the first comparator; a third register configured to store a third count based upon the third reference voltage being input into the first comparator; a fourth register configured to store a fourth count based upon a first input voltage being input into the first comparator, wherein the first input voltage is the voltage to be converted to a digital value by the ADC; and an output circuit configured to calculate a digital value for the first input voltage based upon the first, second, third, and fourth counts.
Multiplying digital-to-analog converter (MDAC) with nonlinear calibration
A system includes a multiplying digital-to-analog converter (MDAC). The system also includes an input-side component coupled to the MDAC and configured to provide a code to the MDAC. The system also includes a reference voltage source coupled to the MDAC and configured to provide a reference voltage to the MDAC. The MDAC comprises a nonlinear calibration circuit configured to adjust an output of the MDAC nonlinearly based on the code, the reference voltage, and an output of the nonlinear calibration circuit.
BACKGROUND TIMING SKEW ERROR MEASUREMENT FOR RF DAC
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.
VCO-BASED CONTINUOUS-TIME PIPELINED ADC
VCO ADCs consume relatively little power and require less area than other ADC architectures. However, when a VCO ADC is implemented by itself, the VCO ADC can have limited bandwidth and performance. To address these issues, the VCO ADC is implemented as a back end stage in a VCO-based continuous-time (CT) pipelined ADC, where the VCO-based CT pipelined ADC has a CT residue generation front end. Optionally, the VCO ADC back end has phase interpolation to improve its bandwidth. The pipelined architecture dramatically improves the performance of the VCO ADC back end, and the overall VCO-based CT pipelined ADC is simpler than a traditional continuous-time pipelined ADC.
SYSTEM AND METHOD FOR BACKGROUND CALIBRATION OF TIME INTERLEAVED ADC
The present invention discloses a method of calibrating time interleaved analog to digital converter comprising: sampling a common input signal, said sampling is performed by an array of sub analog to digital converters, each generating individual digital analog equivalent outputs with sampling time errors, said digital outputs are fed to sampling time error estimation circuitry to calculate a digital output proportional to sampling time error between two consecutive channels, without any restriction on input signal or ADC channel design, said timing skew estimator circuitry composed of generating a delayed output of one of the two consecutive ADC channels, channel first and channel second and subtracting the said delayed output with digital output of the said second channel and producing the first subtracted output and output of said second channel subtracted with said first channel output delayed by sampling delay between the two consecutive channels and producing the second subtracted delayed output, absolute value of the said first subtracted output and said second subtracted delayed output is monitored for peak value of both for a fixed time duration and then subtracted values of the said peak values are the estimation of sampling time error between the said two consecutive channels, same process is repeated to each consecutive ADC channels of the said ADC array.
CURRENT STEERING DIGITAL TO ANALOG CONVERTER (DAC) SYSTEM TO PERFORM DAC STATIC LINEARITY CALIBRATION
In accordance with the present invention a system and method for calibration of the current steering DAC is elaborated which helps to reduce design complexity and reduce silicon area required in the design. Present invention is utilising a clocked comparator and plurality of switch transistors 405,305 and AUX DAC in conjunction with digital estimator and digital compensator blocks to estimate the errors in the current sources 406 and compensate the errors using same AUX DAC during normal operation mode.
RECONFIGURABLE DAC IMPLEMENTED BY MEMRISTOR BASED NEURAL NETWORK
A digital to analog converter is constructed using a neural network layer. The converter has inputs for receiving parallel bits of a digital input signal and an output for outputting an analog signal which is based on the digital input. Connecting the input and the output is a neural network layer which is configured to convert the parallel bits into an output analog signal that is representative of the digital input signal. The neural network may be hardwired and the synapses may rely on memristors as programmable elements.
BACKGROUND STATIC ERROR MEASUREMENT AND TIMING SKEW ERROR MEASUREMENT FOR RF DAC
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.