An analog-to-digital converter includes: a voltage-current converter receiving an analog input voltage, generating a first digital signal from the analog input voltage, and outputting a residual current remaining after the first digital signal; a current-time converter converting the residual current into a current time in a time domain; and a time-digital converter receiving the residual time, and generating a second digital signal from the residual time, wherein the first digital signal and the second digital signal are sequences of digital codes representing respective signal levels of the analog input voltage.

A ratiometric analog-to-digital conversion circuit includes a first voltage range operation circuit configured to use a first power supply voltage of a first voltage range, and output an analog signal corresponding to an external input signal; and a second voltage range operation circuit configured to use a second power supply voltage of a second voltage range, generate a digital value by analog-to-digital converting the analog signal, feed back the digital value for analog-to-digital conversion, and output a digital signal corresponding to the digital value and proportional to the input signal.

A switched-capacitor amplifier comprises a comparator, sample and amplification capacitors and a controller to control charge and discharge current sources in dependence on an output signal of the comparator. A closed loop control circuit is configured to determine the delay of the comparator and control an offset of the comparator in response to the determined delay.

An analog-to-digital converter, including a sample/hold circuit; a reference voltage driver; a digital-to-analog converter; a comparator; and a logic circuit, wherein the reference voltage driver includes: a first voltage supplier circuit configured to output an external supply voltage provided from outside of the analog-to-digital converter; a second voltage supplier circuit configured to output a sampled reference voltage that is obtained during a sampling phase based on control signals received from the logic circuit; and a switching driver configured to electrically connect the first voltage supplier circuit to the digital-to-analog converter during a first conversion phase after the sampling phase based on the control signals received from the logic circuit, and to electrically connect the second voltage supplier circuit to the digital-to-analog converter during a second conversion phase based on the control signals received from the logic circuit.

A SAR ADC (50) is disclosed. It comprises a differential input port having a first input (V.sub.inP) configured to receive a first input voltage and a second input (V.sub.inN) configured to receive a second input voltage, of opposite polarity compared with first input voltage. Furthermore, it comprises a (300) having a first sub circuit (310P) comprising a first plurality of capacitors (2C.sub.u, C.sub.u), each connected to a common node (320P) of the first sub circuit (310P) with a first terminal, and a second sub circuit (310N) comprising a second plurality of capacitors (2C.sub.u, C.sub.u), each connected to a common node (320N) of the second sub circuit (310N) with a first terminal. For each capacitor (2C.sub.u, C.sub.u) of the first plurality of capacitors, the first sub circuit (310P) comprises a first switch (S4) connected between the first input (V.sub.inP) of the SAR ADC and a second terminal of that capacitor, a second switch (S.sub.2) connected between a first reference-voltage input (V.sub.rP) and the second terminal of that capacitor, a third switch (S.sub.1) connected between a second reference-voltage input (V.sub.rN) and the second terminal of that capacitor, and a capacitive device (X.sub.P) connected between the second input (V.sub.inN) of the SAR ADC and the second terminal of that capacitor. The second sub circuit is arranged in a similar way.

Systems and methods related to successive approximation register (SAR) analog-to-digital converters (ADCs) are provided. A method for performing successive approximation registers (SAR) analog-to-digital conversion includes comparing, using a comparator, a first digital-to-analog (DAC) output voltage to a sampled analog input voltage to generate a comparison result including a first positive output and a first negative output; and gating, using gating logic circuitry, at least one of the first positive output or the first negative output of the comparator to next logic circuitry, the gating based at least in part on a digital feedback comprising information associated with at least one of an opposite polarity of the first positive output or an opposite polarity of the first negative output.

High speed, high dynamic range SAR ADC method and architecture. The SAR DAC comparison method can make fewer comparisons with less charge/fewer capacitors. The architecture makes use of a modified top plate switching (TPS) DAC technique and therefore achieves very high-speed operation. The present disclosure proffers a unique SAR ADC method of input and reference capacitor DAC switching. This benefits in higher dynamic range, no external decoupling capacitory requirement, wide common mode range and overall faster operation due to the absence of mini-ADC.

The present application discloses a successive approximation register analog-to-digital converter with passive noise shaping, which comprises: switch capacitor arrays for acquiring analog input signals; a noise shaping circuit which is a passive integral network, the network has input ends connected respectively with output ends of the two switch capacitor arrays and for acquiring output signals of the two switch capacitor arrays, is composed of a plurality of sub passive integrators, and reconfigures the plurality of sub passive integrators to different circuit forms; a comparator which has two input ends connected respectively with output ends of the passive integral network and an output end connected with an input end of a logic circuit, and is configured to compare magnitudes of the output signals of the noise shaping circuit.

An analog-to-digital converter (ADC) circuit comprises one or more most-significant-bit (MSB) capacitors having first ends connected to a voltage comparator and one or more least-significant-bit (LSB) capacitors having first ends connected to the comparator. The circuit further comprises a first switching circuit for each MSB capacitor, configured to selectively connect the second end of the respective MSB capacitor to (a) an input voltage, for sampling, (b) a ground reference, during portions of a conversion phase, and (c) a first conversion reference voltage, for other portions of the conversion phase. The circuit still further comprises a second switch circuit, for each LSB capacitor, configured to selectively connect the second end of the respective LSB capacitor between (d) the ground reference, during portions of the conversion phase, and (e) a second conversion reference voltage, for other portions of the conversion phase, the second conversion reference voltage differing from the first.

An analog-to-digital converter is provided. The analog-to-digital converter includes: a sample/hold circuit; a digital-to-analog converter; a plurality of comparison circuits; a control logic; and a digital register, wherein the plurality of comparison circuits include: a first comparison circuit configured to output a first comparison result signal in a first operation period; a second comparison circuit configured to, in a second operation period, calibrate an offset of a second comparison result signal based on a reference signal corresponding to the first comparison result signal among a plurality of reference signals and output the calibrated second comparison result signal; and a third comparison circuit configured to, in a third operation period, calibrate an offset of a third comparison result signal based on a reference signal corresponding to the calibrated second comparison result signal and output the calibrated third comparison result signal.