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.

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.

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.

Testing of the noise-shaping circuitry within a successive approximation register (“SAR”) analog-to-digital converter (“ADC”) (“SAR ADC”) to ensure it will function as expected, while also providing a method for calibrating the coefficients of the noise-shaping circuitry. Programmable/trimmable circuit component(s) can be used to calibrate the coefficient(s) of the SAR ADC. Digital logic within the SAR engine enables it to selectively skip portions of the ADC conversion process and to use voltage references rather than an analog voltage input signal in sample mode during such test/calibration modes.

A voltage-to-delay converter converts input signals into delay signals, and includes: a first stage for receiving the input signals and for generating intermediate output signals, wherein timing of the intermediate output signals corresponds to voltages of the input signals, and wherein the first stage has a voltage source for providing a rail-to-rail voltage; and a second stage for receiving the intermediate output signals and for generating rail-to-rail output signals, wherein timing of the rail-to-rail output signals corresponds to the timing of the intermediate output signals, and wherein voltage of the rail-to-rail output signals corresponds to the rail-to-rail voltage. A voltage-to-delay converter block is also described. A circuit for receiving differential input signals, generating corresponding output signals, and removing common mode signals from the output signals is also described.

In a semiconductor integrated circuit, a first generation circuit generates a common mode voltage of a differential signal. A second generation circuit generates temperature information according to the common mode voltage. The temperature information is information corresponding to a characteristic of an amplifier circuit related to an ambient temperature. A correction circuit corrects a first reference voltage and a second reference voltage according to the temperature information. A comparator includes a first input node to which a first signal line is electrically connected; a second input node to which a second signal line is electrically connected; a third input node to which the corrected first reference voltage is input; and a fourth input node to which the corrected second reference voltage is 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.

In a semiconductor integrated circuit, a first generation circuit generates a common mode voltage of a differential signal. A second generation circuit generates temperature information according to the common mode voltage. The temperature information is information corresponding to a characteristic of an amplifier circuit related to an ambient temperature. A correction circuit corrects a first reference voltage and a second reference voltage according to the temperature information. A comparator includes a first input node to which a first signal line is electrically connected; a second input node to which a second signal line is electrically connected; a third input node to which the corrected first reference voltage is input; and a fourth input node to which the corrected second reference voltage is input.

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).

An apparatus for calibrating a differential circuit that includes a differential integrator having an input, a gain, and an output connected to a comparator. The differential integrator output is chargeable to a threshold prior to an integration period. The differential integrator integrates the input during the integration period such that the differential integrator output goes toward zero from the threshold. The comparator detects the output of the differential integrator reaching zero. The apparatus includes a closed-loop gain trim circuit to perform a coarse calibration to adjust and set the gain of the differential integrator and a reference generator that generates the threshold to which the differential integrator output is pre-charged. The reference generator is trimmable during a fine calibration to adjust and set the threshold to correct for residual gain error in the differential circuit remaining after the coarse calibration is performed.