A capacitive sampling circuit comprises: a first-differential-input-terminal, configured to receive a first one of a pair of differential-input-signals; a second-differential-input-terminal, configured to receive the other one of the pair of differential-input-signals; a capacitive-circuit-output-terminal, configured to provide a sampled-output-signal; a plurality of first-sampling-capacitors, each having a first-plate and a second-plate; a plurality of reference-voltage-terminals, each configured to receive a respective reference-voltage; and a first-capacitor-first-plate-switching-block configured to selectively connect the first-plate of each of the plurality of first-sampling-capacitors to either: (i) the first-differential-input-terminal; or (ii) a respective one of the plurality of reference-voltage-terminals; and a first-capacitor-second-plate-switch, configured to selectively connect or disconnect the second-plate of each of the plurality of first-sampling-capacitors to the second-differential-input-terminal.

Capacitor structures with pitch-matched capacitor unit cells are described. In an embodiment, the capacitor unit cells are formed by interdigitated finger electrodes. The finger electrodes may be pitch-matched in multiple metal layers within a capacitor unit cell, and the finger electrodes may be pitch-matched among an array of capacitor unit cells. Additionally, border unit cells may be pitch-matched with the capacitor unit cells.

An A/D conversion device, which operates in one mode including at least one of a mode, a cyclic mode, and a hybrid mode, includes: a first block that processes an analog input signal by a first amplifier; a second block including a second amplifier; a quantization unit that quantizes one of outputs of the first and second blocks; and a control circuit that switches the mode to perform a control corresponding to the mode.

Successive-approximation-register (SAR) analog-to-digital conversion technique continues to be one of the most popular analog-to-digital conversion techniques, due to their versatility, which allows providing high resolution output or high conversion rates. In addition, SAR analog-to-digital converters (ADC) have a modest circuit complexity that results in low-power dissipation. A SAR ADC is, typically, composed of a single comparator, a bank of capacitors and switches, in addition to, a control digital logic. However, the comparator input capacitance is input-signal dependent, and hence introduces non-linearity to the transfer characteristics of the ADC. A simple technique is devised to significantly reduce this non-linearity, by pre-distorting the sampled-and-held input signal using the same comparator input capacitance.

The present invention is a system and method for providing a modified Digital-to-Analog converter (DAC) for use in a time-interleaved successive-approximation-register (SAR) analog-to-digital converter (ADC), the DAC including grouping of capacitance electrodes by Bit in a DAC, thereby reducing parasitic capacitances, and substantially improving power efficiency and speed to operate at GHz frequencies.

A calibratable switched-capacitor voltage reference and an associated calibration method are described. The voltage reference includes dynamic diode elements providing diode voltages, input capacitor(s) for sampling input voltages, base-emitter capacitor(s) for sampling one diode voltage with respect to a ground, dynamically trimmable capacitor(s) for sampling the one diode voltage with respect to another diode voltage, and an operational amplifier coupled to the capacitors for providing reference voltage(s) based on the sampled input and diode voltages and on trims of the trimmable capacitor(s). The voltage reference can be configured as a first integrator of a modulator stage of a delta-sigma analog-to-digital converter.

A digital-to-analog converter comprises a plurality of first digital-to-analog converter cells configured to generate a first analog signal based on first digital data, wherein the first digital-to-analog converter cells of the plurality of first digital-to-analog converter cells are coupled to a first output node for coupling to a first load. Further, the digital-to-analog converter comprises a plurality of second digital-to-analog converter cells configured to generate one or more second analog signals based on second digital data, wherein the second digital-to-analog converter cells of the plurality of second digital-to-analog converter cells are coupled to one or more second output nodes, and wherein the plurality of first digital-to-analog converter cells and the plurality of second digital-to-analog converter cells are coupled to a power supply node for coupling to a mutual power supply.

A multiplying digital to analog converter (MDAC) includes a first resistor configured to be selectively connected to a current output node based on a first bit of a first portion of an input digital code and a second resistor configured to be selectively connected to the current output node based on a second bit of the first portion of the input digital code. A resistance of the second resistor is a resistance of the first resistor scaled by a factor. The MDAC further includes a first capacitor configured to be selectively connected to the current output node based on the first bit of the first portion and a second capacitor configured to be selectively connected to the current output node based on the second bit of the first portion. A capacitance of the second capacitor is a capacitance of the first capacitor scaled by an inverse of the factor.

An analog to digital converter device includes a capacitor array, a digital logic circuit, and a comparator circuit. The capacitor array includes first capacitors, a capacitor to be calibrated, and compensation capacitors. The digital logic circuit performs a calibration on the capacitor to be calibrated, in order to calibrate a weighed value of the capacitor to be calibrated according to a decision signal, and converts an input signal to bits via the capacitor array after the calibration is performed. The comparator circuit compares a testing signal with a predetermined voltage to generate the decision signal. The testing signal is generated by the first capacitors and the capacitor to be calibrated in response to the calibration. The digital logic circuit further selects at least one of the compensation capacitors, in order to adjust a digital code corresponding to a calibrated weighed value to be an integer expressed by the bits.

A calibratable switched-capacitor voltage reference and an associated calibration method are described. The voltage reference includes dynamic diode elements providing diode voltages, input capacitor(s) for sampling input voltages, base-emitter capacitor(s) for sampling one diode voltage with respect to a ground, dynamically trimmable capacitor(s) for sampling the one diode voltage with respect to another diode voltage, and an operational amplifier coupled to the capacitors for providing reference voltage(s) based on the sampled input and diode voltages and on trims of the trimmable capacitor(s). The voltage reference can be configured as a first integrator of a modulator stage of a delta-sigma analog-to-digital converter.