H03M1/1014

Methods of filtering reference voltage noise

A voltage reference noise filter is provided that substantially eliminates noise with minimal external components for any circuit where the reference load current is a constant load and the circuit uses external components that have values that may vary with temperature, over time, and the like. The drift on an output of a voltage reference due to variation of resistor of the external filter is mitigated by moving the external resistor onto the chip containing the circuit. The voltage drop across the resistor is digitally compensated by a scaling factor determined during calibration. When more than one converter is provided on the chip, a further adjustment to the outputs of the converters is made based on the number of converters powered on or off. Also, error in output of converters due to mismatch among the converters is digitally compensated by a further scaling factor.

DIGITAL TO ANALOG CONVERTER DEVICE AND CALIBRATION METHOD
20200274544 · 2020-08-27 ·

A digital-to-analog converter (DAC) device includes a DAC circuitry and a calibration circuitry. The DAC circuitry includes first and second DAC circuits which generate first and second signals according to an input pattern. The input pattern includes at least one of first logic value and at least one of second logic value that have different numbers. The calibration circuitry performs a calibration operation according to first and second comparison results, to generate a control signal for controlling the second DAC circuit. The first comparison results are comparison results of the first and the second signals when the input pattern is a first pattern, the second comparison results are comparison results of the first and the second signals when the input pattern is a second pattern, and the first pattern is inverse to the second pattern.

TECHNIQUES TO IMPROVE LINEARITY OF R-2R LADDER DIGITAL-TO-ANALOG CONVERTERS (DACs)

An integrated circuit includes a digital-to-analog converter (DAC) core including a plurality of thermometric arms and an R-2R ladder, the DAC core to convert a DAC code to an analog signal. The integrated circuit includes additional components as well. A differential non-linearity (DNL) calibration circuit outputs DNL coefficients based on the DAC code. A memory stores a value indicative of a product of a resistor temperature coefficient (TC) and a resistor self-heating coefficient (SHC). A current DAC (IDAC) couples to the R-2R ladder. A self-heating calibration circuit generates a self-heating trim code based on the value from the memory. An adder adds a value indicative of the DNL coefficients with the self-heating trim code to generate an IDAC trim code and provides the IDAC trim code to the IDAC to trim the R-2R ladder.

TRANSCEIVER WITH IN-PHASE AND QUADRATURE-PHASE COUPLING CORRECTION

A transceiver system includes a clock generator and an analog-to-digital circuit (ADC). The transceiver system also includes a coupling correction circuit coupled to the clock generator and to the ADC, wherein the coupling correction circuit is configured to provide an in-phase correction and a quadrature-phase correction to a signal received by the ADC.

Analog-to-digital converters with resistor digital-to-analog converters for reference voltage tuning

Circuits for an analog-to-digital converter and methods of operating an analog-to-digital converter. A resistor digital-to-analog converter (RDAC) has a first reference node coupled to a first current source, a second reference node coupled to a second current source, an input port configured to receive a first voltage, and an output port coupled to a buffer. The RDAC is configured to generate a second voltage including a first voltage shift from the first voltage and to supply the second voltage from the output port of the RDAC to the buffer.

SIGNAL DUTY CYCLE ADAPTIVE-ADJUSTMENT CIRCUIT AND METHOD FOR RECEIVING TERMINAL

The present invention relates to a signal duty cycle adaptive-adjustment circuit and method for a receiving terminal. In one embodiment, the circuit includes an analog level comparison circuit, a preprocessing circuit, a first path switch, a second path switch, a decoding circuit, a parameter extraction and estimation circuit, an error generation circuit, a filter feedback circuit and a digital-to-analog conversion circuit. The analog level comparison circuit receives a valid signal according to a reference level to generate a duty cycle signal. The preprocessing circuit preprocesses the duty cycle signal. When the first path switch is turned on, the parameter extraction and estimation circuit acquires duty cycle information from the duty cycle signal to generate a duty cycle deviation. The error generation circuit processes the duty cycle deviation to generate an error signal. The filter feedback circuit and the digital-to-analog conversion circuit filter the error signal and then convert the error signal into an analog voltage signal, which is connected to the analog level comparison circuit to serve as a reference level. When the second path switch is turned on, the decoding circuit decodes the duty cycle signal.

TECHNIQUES TO IMPROVE LINEARITY OF R-2R LADDER DIGITAL-TO-ANALOG CONVERTERS (DACs)

An integrated circuit includes a digital-to-analog converter (DAC) core including a plurality of thermometric arms and an R-2R ladder, the DAC core to convert a DAC code to an analog signal. The integrated circuit includes additional components as well. A differential non-linearity (DNL) calibration circuit outputs DNL coefficients based on the DAC code. A memory stores a value indicative of a product of a resistor temperature coefficient (TC) and a resistor self-heating coefficient (SHC). A current DAC (IDAC) couples to the R-2R ladder. A self-heating calibration circuit generates a self-heating trim code based on the value from the memory. An adder adds a value indicative of the DNL coefficients with the self-heating trim code to generate an IDAC trim code and provides the IDAC trim code to the IDAC to trim the R-2R ladder.

Error calibration apparatus and method

An error calibration apparatus and method are provided. The method is adapted for calibrating a machine learning (ML) accelerator. The ML accelerator achieves computation by using an analog circuit. An error between an output value of one or more computing layers of a neural network and a corresponding corrected value is determined. The computation of the computing layers is achieved by the analog circuit. A calibration node is generated according to the error. The calibration node is located at the next layer of the computing layers. The calibration node is used to minimize the error. The calibration node is achieved by a digital circuit. Accordingly, error and distortion of the analog circuit could be reduced.

GAIN CALIBRATION DEVICE AND METHOD FOR RESIDUE AMPILIFIER OF PIPELINE ANALOG TO DIGITAL CONVERTER
20200136633 · 2020-04-30 ·

A gain calibration device for an ADC residue amplifier includes a DAC and a flash ADC. The DAC is configured to convert the digital signal to an analog signal, and the DAC includes a calibration module used in the gain calibration of the ADC residual amplifier. The flash ADC is configured to generate a digital signal, the flash ADC includes a plurality of comparators, the total number of the plurality of comparators is equal to the number of output bits of the flash ADC, and the comparators are configured to be unevenly distributed in an input range.

Transceiver with in-phase and quadrature-phase coupling correction

A transceiver system includes a clock generator and an analog-to-digital circuit (ADC). The transceiver system also includes a coupling correction circuit coupled to the clock generator and to the ADC, wherein the coupling correction circuit is configured to provide an in-phase correction and a quadrature-phase correction to a signal received by the ADC.