A voltage-to-time-to-digital converter (VTDC) and conversion method are provided using a coarse analog-to-digital converter (ADC). A voltage-to-time converter (VTC) receives an analog input voltage-differential signal with a first time duration and supplies an analog first time-differential signal. An ADC receives the input voltage-differential signal and supplies a first digital code representing m bit values. A time-to-digital converter (TDC) receives a second time-differential signal with a second time duration derived from the first time duration. The TDC supplies an output digital code representing p bit values, where p>m. In one aspect the first digital code programs an initial set of TDC residue generators. In another aspect, a dither circuit controls the second time duration in response to a pseudo random signal combined with the first digital code.

A distance measuring method and an electronic laser distance measuring module, in particular for use in a distance measuring apparatus, especially configured as a laser tracker, tachymeter, laser scanner, or profiler, for fast signal detection with an analog-to-digital converter, wherein conversion errors that arise in the context of a signal digitization, in particular timing, gain and offset errors of the ADC, are compensated for by means of variation of the sampling instants.

A dither capacitor, separate from the capacitor sampling the input signal, can be used to inject the additive dither in the switched-capacitor network of the track and hold circuit. This implementation can be referred to as a split-capacitor dither injection. The dither capacitor can be connected to a summing node of the switched-capacitor network. Using a separate capacitor allows the dither to be isolated from the capacitor that is sampling the input signal and avoids kick-back errors.

The present disclosure relates to the field of semiconductor integrated circuits, and to a method for calibrating a capacitor voltage coefficient of a high-precision successive approximation analog-to-digital converter (SAR ADC). The method includes: calibrating a voltage coefficient; obtaining a sampled charged charge according to a capacitance model with the voltage coefficient; according to an INL value obtained by testing, first verifying whether a maximum value of INL occurs in the place shown in Equation 3, then obtaining two very close second-order capacitor voltage coefficients according to Equation 4, and taking an average value thereof as a second-order capacitor voltage coefficient; and then calibrating the second-order capacitor voltage coefficient in a digital domain. In the present disclosure, a capacitor voltage coefficient can be extracted based on INL and the capacitor voltage coefficient is calibrated at a digital backend without adding an analog calibration circuit, thereby improving conversion accuracy of the ADC.

An apparatus and method for sampling an analog signal with analog-to-digital converters (ADCs) is disclosed. The ADCs may be separated into a group of interleaved ADCs and a spare ADC. The interleaved ADCs can sample the analog signal according to an interleaving sequence. An interleaved ADC controller can monitor the inactivity of the spare ADC and can replace one of the interleaved ADCs in the interleaving sequence with the spare ADC based on the inactivity.

The present disclosure relates to the field of semiconductor integrated circuits, and to a method for calibrating a capacitor voltage coefficient of a high-precision successive approximation analog-to-digital converter (SAR ADC). The method includes: calibrating a voltage coefficient; obtaining a sampled charged charge according to a capacitance model with the voltage coefficient; according to an INL value obtained by testing, first verifying whether a maximum value of INL occurs in the place shown in Equation 3, then obtaining two very close second-order capacitor voltage coefficients according to Equation 4, and taking an average value thereof as a second-order capacitor voltage coefficient; and then calibrating the second-order capacitor voltage coefficient in a digital domain. In the present disclosure, a capacitor voltage coefficient can be extracted based on INL and the capacitor voltage coefficient is calibrated at a digital backend without adding an analog calibration circuit, thereby improving conversion accuracy of the ADC.

A successive approximation register, SAR, analog-to-digital converter, ADC, (400) is described. The SAR ADC (400) includes: a track and hold circuit (414) configured to sample an analog input signal (410); a comparator (416) coupled to the track and hold circuit and configured to compare the sampled analog input signal (410) with a DAC (444) output voltage; and a feedback path (422) that comprises a digital-to-analog converter, DAC, (444) configured to generate the reference voltage that approximates the input analog signal (410). The SAR ADC (400) further includes a dither circuit (468) coupled to or located in the feedback path (422) and arranged to add a dither signal at an input of the DAC (444) in a first time period and subtract the dither signal from the output digital signal routed via the feedback path (422) and input of the DAC (444) in a second time period during a conversion phase of the SAR ADC (400).

A pixel circuit and method for operating the same is disclosed. The circuit includes a first driver circuit coupled to receive an analog pixel data, transfer signal and reset signal. The circuit further includes a source follower transistor having a source terminal coupled to a column node, and a gate terminal coupled to the first driver circuit. The circuit further includes a second driver circuit coupled to receive the transfer signal and the reset signal. The second driver circuit is capacitively coupled to the column node through a first capacitor.

A multi-input analog-to-digital converter (ADC), i.e., a single ADC, can receive multiple analog input signals and generate multiple digital outputs. To combine multiple analog input signals into a single multi-input ADC, the multi-input ADC would typically include multiple track and hold (T/H) circuits and an adder, which can consume a significant amount of power and incur large cost overhead. An improved approach is to combine multiple inputs through a unique T/H circuit in the front-end of the ADC. The multiple analog input signals can be aggregated using code sequences, without requiring a significant amount of external circuits.

A digital to time converter (DTC) system is disclosed. The DTC system comprises a DTC circuit configured to generate a DTC output clock signal at a DTC output frequency, based on a DTC code. In some embodiments, the DTC system further comprises a calibration circuit comprising a period error determination circuit configured to determine a plurality of period errors respectively associated with a plurality consecutive edges of the DTC output clock signal. In some embodiments, each period error of the plurality of period errors comprises a difference in a measured time period between two consecutive edges of the DTC output clock signal from a predefined time period. In some embodiments, the calibration circuit further comprises an integral non-linearity (INL) correction circuit configured to determine a correction to be applied to the DTC code based on a subset of the determined period errors.