A method for self-calibration of reference voltage drop in a Digital to Analog Converter (DAC) includes measuring each one of a plurality of thermometric weightages associated with a respective one of a plurality of thermometric bits, wherein the DAC includes a plurality of sub-binary bits and the plurality of thermometric bits. For each sequentially increasing combination of thermometric bit settings including at least two thermometric bits coupled to a high reference voltage and each sub-binary bit coupled to a low reference voltage, performing the steps of: determining a respective combined weightage correction; adding the combined weightage correction to the highest order bit of the combination of thermometric bit settings; and incrementing a number of bits of the combination of thermometric bit settings in response to the number of bits of the sequential combination being less than a total number of the plurality of thermometric bits.

A method of weight calibration in a DAC (25) is disclosed. The DAC (25) comprises an input port (100) for receiving a sequence of digital input words (x[n]), each representing a digital input sample, and a digital control circuit (110) configured to encode each digital input word (x[n]) into a control word (z[n]) representing the same digital input sample. Each bit (Z.sub.i) in the control word (z[n]) has a corresponding bit weight (w.sub.i) and is in the following considered to adopt values in {−1, 1}. Furthermore, the DAC (25) comprises a set (120) of analog weights, each associated with a unique one of the bits (Z.sub.i) in the control word (z[n]), and summation circuitry (130) configured to generate an analog sample corresponding to the digital input sample by summing the bits in the control word (Z.sub.i) weighted by the respective associated analog weights. The DAC (25) also has an output (140) for outputting the analog sample. The method comprises, during a measurement procedure, for a first set of at least one bit of the control word (z[n]), generating (300) the bits of the first set, such that a first sum of the bits in the first set weighted by their respective bit weights is, on average, above zero. Furthermore, the method comprises, during the measurement procedure, for a second set of at least one bit of the control word (z[n]), generating (310) the bits of the second set, such that a second sum of the bits in the second set weighted by their respective bit weights is, on average, below zero and such that the sum of the first sum and the second sum is, on average, equal to zero. The method also comprises detecting (330) a DC level at the output of the DAC during the measurement procedure. The method further comprises adjusting (340) at least one analog weight in response to the detected DC level. A corresponding DAC, a corresponding electronic apparatus, and a corresponding integrated circuit are also disclosed.

Analog gain correction circuitry and analog switching clock edge timing correction circuitry can provide coarse correction of interleaving errors in radio-frequency digital-to-analog converters (RF DACs), such as may be used in 5G wireless base stations. The analog correction can be supplemented by digital circuitry configured to “pre-cancel” an interleaving image by adding to a digital DAC input signal a signal equal and opposite to an interleaving image created by the interleaving DAC, such that the interleaving image is effectively mitigated. Error correction control parameters can be periodically adjusted for changes in temperature by a controller coupled to an on-chip temperature sensor. A model useful for understanding the sources of error in interleaving DACs is also described.

A self-calibrating digital-to-analog converter (DAC) is disclosed. The self-calibrating DAC includes a DAC including a least significant bit (LSB) side resistor network and a most significant bit (MSB) side resistor network. At least the MSB side resistor network includes a plurality of trimmable resistors. A resistance to frequency converter coupled with an output of the DAC is included to generate a frequency f.sub.L based on a value of the LSB side resistor network or the MSB side resistor network. A monitor is included to generate a counter value by comparing f.sub.L with a high frequency clock having a constant frequency f.sub.H. A memory is included to store at least two counter values generating by comparing f.sub.L and f.sub.H once when the LSB side resistor network is connected while the MSB side resistor network is floating and once when the LSB side resistor network is floating while only one of the resistors in the MSB side resistor network is connected and all other resistors in the MSB side resistor network are floating. A comparator is included to compare the at least two counter values. A trimming controller is included to generate a trimming signal to trim one of the plurality of trimmable resistors based on an output of the comparator.

An N-channel interleaved Analog-to-Digital Converter (ADC) has a variable delay added to each ADC's input sampling clock. The variable delays are each programmed by a Successive-Approximation-Register (SAR) during calibration to minimize timing skews between channels. Each channel receives a sampling clock with a different phase delay. The sampling clocks are overlapping multi-phase clocks rather than non-overlapping. Overlapping the multi-phase clocks allows the sampling pulse width to be enlarged, providing more time for the sampling switch to remain open and allow analog voltages to equalize through the sampling switch. Higher sampling-clock frequencies are possible than when non-overlapping clocks are used. The sampling clock is boosted in voltage by a bootstrap driver to increase the gate voltage on the sampling switch, reducing the ON resistance. Sampling clock and component timing skews are reduced to one LSB among all N channels.

Embodiments of the present disclosure include a differential digital delay line analog-to-digital converter (ADC), comprising differential digital delay lines including series coupled delay cells, wherein a delay time of a first delay line is controlled by a first input of the ADC and a delay time of a second delay line is controlled by a second input of the ADC. The ADC includes a pair of bypass multiplexers coupled at a predefined node location in the series coupled delay cells, latches each coupled with the series coupled delay cells, a converter circuit coupled with the plurality of latches configured to convert data from the latches into an output value of the ADC, and logic circuits configured to select data from the series coupled delay cells to the latches depending on a selected resolution of the differential digital delay line analog-to-digital converter.

Calibration of continuous-time (CT) residue generation systems can account and compensate for mismatches in magnitude and phase that may be caused by fabrication processes, temperature, and voltage variations. In particular, calibration may be performed by providing one or more known test signals as an input to a CT residue generation system, analyzing the output of the system corresponding to the known input, and then adjusting one or more parameters of a forward and/or a feedforward path of the system so that the difference in transfer functions of these paths may be reduced/minimized. Calibrating CT residue generation systems using test signals may help decrease the magnitude of the residue signals generated by such systems, and, consequently, advantageously increase an error correction range of such systems or of further stages that may use the residue signals as input.

A digital-to-analog conversion circuit, comprising: an R−2R resistive network (10) configured to be connected between an output end and a ground end; an output voltage selection unit (20) configured to be connected between the output end of the R−2R resistive network (10) and a voltage output terminal; an output voltage trimming unit (30), wherein the output voltage trimming unit (30) is provided between a 2R resistor on at least one branch of the R−2R resistive network (10) and the ground end.

An analog-to-digital conversion circuit (100) is disclosed. It comprises a switched-capacitor SAR-ADC, (110) arranged to receive an analog input signal (x(t)) and a clock signal, to sample the analog input signal (x(t)), and to generate a sequence (W(n)) of digital output words corresponding to samples of the analog input signal (x(t)), wherein the SAR-ADC (110) is arranged to generate a bit of the digital output word per cycle of the clock signal. It further comprises a clock-signal generator (120) arranged to supply the clock signal to the SAR-ADC (110), and a post-processing unit (140) adapted to receive the sequence (W(n)) of digital output words and generate a sequence of digital output numbers (y(n)), corresponding to the digital output words, based on bit weights assigned to the bits of the digital output words. The bit weights are selected to compensate for a decay of a signal internally in the SAR-ADC (110).

Numerous examples are disclosed for performing calibration of various electrical parameters in a deep learning artificial neural network. In one example, a system comprises a digital-to-analog converter for receiving an input of k bits and generating a first analog output, a mapping scalar for converting the first analog output into a second analog output, and an analog-to-digital converter for generating an output of n bits from the second analog output, where n is a different value than k.