A digital-to-time converter (DTC) and methods of calibrating the same reduces or mitigates nonlinearity and thus improves DTC performance. A slope of a voltage signal of the DTC is calibrated using a capacitor and a comparator. Capacitance of the capacitor and/or maximum current of a current source is adjusted to configure the comparator to output a signal during a second phase when a reference voltage signal is at or above a first level and below a second level. Calibrating gain of the DTC includes adjusting a time difference between an output signal of the DTC set at a first digital code value and the output signal of the DTC set at a second digital code value to be one period of a clock signal input to the DTC. Calibrating integral nonlinearity of the DTC includes measuring a time period for each of multiple digital code values of the DTC.

An input stage for an analog/digital converter, an analog/digital converter and a method for testing analog/digital converters with successive approximation are disclosed. At an input stage, an input signal is supplied via a first transistor arrangement of a sampling capacitor arrangement. The sampling capacitor arrangement can be optionally connected to ground or to a reference voltage by way of a second transistor arrangement and a switch apparatus.

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.

A system and method for equalization of a linear or non-linear system. The system includes an adder configured to add an analog reference signal and an input signal, a processing system configured to process a sum of the analog reference signal and the input signal, a non-linear equalizer (NLEQ) configured to process an output of the processing system to remove a distortion incurred by the processing system, a calibration circuitry configured to generate a reconstructed reference signal in digital domain based on measurement of the analog reference signal, and generate coefficients for the NLEQ based on the reconstructed reference signal and the output of the processing system, and a subtractor configured to subtract the reconstructed reference signal from an output of the NLEQ. The analog reference signal may be a sinusoid including single or multiple tones of sinusoids. The non-linear system may be an analog-to-digital converter (ADC).

A digital-to-time converter (DTC) and methods of calibrating the same reduces or mitigates nonlinearity and thus improves DTC performance. A slope of a voltage signal of the DTC is calibrated using a capacitor and a comparator. Capacitance of the capacitor and/or maximum current of a current source is adjusted to configure the comparator to output a signal during a second phase when a reference voltage signal is at or above a first level and below a second level. Calibrating gain of the DTC includes adjusting a time difference between an output signal of the DTC set at a first digital code value and the output signal of the DTC set at a second digital code value to be one period of a clock signal input to the DTC. Calibrating integral nonlinearity of the DTC includes measuring a time period for each of multiple digital code values of the DTC.

A method for calibrating currents includes performing a first sorting operation on a plurality of first current sources according to current levels generated by the first current sources, performing a second sorting operation on a plurality of second current sources according to current levels generated by the second current sources, determining a first switching sequence for the first plurality of current sources according to a result of the first sorting operation, and determining a second switching sequence for the second plurality of current sources according to a result of the second sorting operation and the first switching sequence. The plurality of first current sources have a same target current value, and the plurality of second current sources have a same target current value.

A pipeline analog to digital converter includes converter circuitries and a calibration circuitry. The converter circuitries sequentially convert an input signal into first digital codes. A first converter circuitry in the converter circuitries performs a quantization according to a first signal to generate a first corresponding digital code in the first digital codes, and the first signal is a signal, which is processed by the first converter circuitry, of the input signal and a previous stage residue signal. The calibration circuitry combines the first digital codes to output a second digital code, detects whether the quantization is completed to generate first and second valid signals, and determines whether to set the second digital code to be a first predetermined digital code or a second predetermined digital code according to the first and the second valid signals. The second valid signal is a delay signal of the first valid signal.

The present invention discloses a DAC method having signal calibration mechanism used in a DAC circuit having thermometer-controlled current sources generating an output analog signal according to a total current thereof and a control circuit. Current offset values of the current sources are retrieved. The current offset values are sorted to generate a turn-on order, in which the current offset values are separated into current offset groups according to the turn-on order, the signs of each neighboring two groups being opposite such that the current offset values cancel each other when the current sources turn on according to the turn-on order to keep an absolute value of a total offset not larger than a half of a largest absolute value of the current offset values. The current sources are turned on based on the turn-on order according to a thermal code included in an input digital signal.

An apparatus for correcting a mismatch between a first segment and a second segment of a Digital-to-Analog Converter, DAC, is provided. The first segment generates a first contribution to an analog output signal of the DAC based on a first number of bits of a digital input word for the DAC converter, and the second segment generates a second contribution to the analog output signal based on a second number of bits of the digital input word. The apparatus comprises an input configured to receive the digital input word. Further, the apparatus comprises a first processing circuit for the first number of bits comprising a first filter configured to modify the first number of bits in order to generate first modified bits, and a second processing circuit for the second number of bits comprising a second filter configured to modify the second number of bits in order to generate second modified bits. The apparatus additionally comprises an output configured to output a modified digital input word for the DAC. The modified digital input word is based on the first modified bits and the second modified bits.

An analog-to-digital converter comprising a plurality of sampling cells. At least one of the plurality of sampling cells comprises a capacitive element coupled to a cell output of the at least one of the plurality of sampling cells, wherein a cell output signal is provided at the cell output. The at least one of the plurality of sampling cells further comprises a first cell input for receiving an input signal to be digitized, and a second cell input for receiving a calibration signal. Additionally, the at least one of the plurality of sampling cells comprises a first switch circuit capable of selectively coupling the first cell input to the capacitive element based on a clock signal, and a second switch circuit capable of selectively coupling the second cell input to the capacitive element, wherein a size of the second switch circuit is smaller than a size of the first switch circuit.