A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a common-mode reference voltage generation circuit uses one or more additional sampling switched capacitors to selectively couple the first and second reference voltages to the amplifier input during the gain phase when the input voltage is between the high and low threshold voltages using a switching configuration of switches that are controllable to connect the sampling switched capacitors to the one or more central nodes in the sampling phase, and to connect the amplifier output in feedback to the input sampling circuit in the gain phase while simultaneously connecting the one or more central nodes to the first amplifier input.

The disclosure includes a mechanism for mitigating charge related disturbances in a Successive Approximation Register (SAR) Analog to Digital Converter (ADC) by providing a fine reference connection and a rough reference connection. A switch array is activated to couple a current bit capacitor of a capacitor array to the rough reference connection while a current bit corresponding to the current bit capacitor is determined by a comparator. The switch array is further activated to couple a previous bit capacitor of the capacitor array to the fine reference connection while the current bit capacitor is coupled to the rough reference connection. This separates charge flow on the rough reference connection from capacitors coupled to the fine reference connection.

The disclosure includes an analog to digital converter (ADC). The ADC includes a comparator to compare sample values of an analog signal in an analog domain to reference values to determine digital values in a digital domain. The digital values correspond to the analog signal and may be determined according to successive approximation. The ADC also includes chop switches to modulate the analog signal to increase a frequency of flicker noise in the analog domain. The ADC also includes an un-chop switch to demodulate the digital values in the digital domain prior filtration of the flicker noise by a digital filter.

Methods and systems for an analog-to-digital converter with near-constant common mode voltage may comprise, in an analog-to-digital converter (ADC) having sampling switches on each of two input lines to the ADC, N double-sided and M single-sided switched capacitors on each input line: sampling an input voltage by closing the sampling switches, opening the sampling switches and comparing voltage levels between the input lines, iteratively switching the double-sided switched capacitors between a reference voltage (Vref) and ground, and iteratively switching the single-sided switched capacitors between ground and voltages that may equal Vref/2.sup.x where x ranges from 0 to m1 and m is a number of single-sided switched capacitors per input line. A common mode offset of the ADC may be less than V.sub.ADC.sub._.sub.fs/128+V.sub.ADC.sub._.sub.fs/256+V.sub.ADC.sub._.sub.fs/512+V.sub.ADC.sub._.sub.fs/1024 when m equals 4 and where V.sub.ADC.sub._.sub.fs is the full-scale voltage of the ADC.

A first analog block includes a first plurality of switched capacitors and a second analog block includes a second plurality of switched capacitors. A switch associated with the first plurality of switched capacitors as well as a switch associated with the second plurality of switched capacitors may be configured based on one or more analog functions. The configuring of the first analog and the second analog block may include the configuring of the switch associated with the first plurality of switched capacitors when the analog function is associated with a first single ended signal and the configuring of both the switch associated with the first plurality of switched capacitors and the switch associated with the second plurality of switched capacitors when the analog function is associated with a differential signal.

A semiconductor device according to an aspect of the invention relates to an AD converter that converts a signal level of an analog signal into a digital value by using a comparator, and determines an amount of adjustment of an offset voltage of the comparator based on an offset determination result of the comparator obtained immediately after a least significant bit (LSB) of a digital value output as a conversion result is converted.

An ADC receives a first input signal and a second input signal and outputs a digital signal. The first input signal is a common-mode voltage plus a voltage difference, and the second input signal is the common-mode voltage minus the voltage difference. The ADC includes a voltage conversion circuit and multiple comparators. The voltage conversion circuit generates an intermediate voltage according to the first input signal, the second input signal, and the common-mode voltage. The comparators compare the intermediate voltage with N times a reference voltage, where N is greater than or equal to negative one and less than or equal to one. The intermediate voltage is the common-mode voltage plus or minus M times the voltage difference, where M is two to the power of R, and R is a positive integer.

An analog-to-digital converter of non-binary capacitor array with redundancy bits and its chip. The non-binary capacitor array with redundancy bits comprises a common-mode voltage, analog signal input, no less than one redundancy bit capacitor and multiple capacitors; each capacitor of capacitors with redundancy bits and multiple capacitors is connected in parallel between common-mode voltage and analog signal input and marked in a sequence from highest to lowest/lowest to highest bit; the sum of the capacitance of capacitors from the lowest bit capacitor to an random capacitor must be no less than the capacitance of the higher bit capacitor adjacent to the random capacitor. The ratio of the capacitance of each capacitor to the capacitance of unit capacitor is set to be positive. The capacitor array is applied into an analog-to-digital converter or fabricated as a chip.

Methods and systems for an analog-to-digital converter with near-constant common mode voltage may comprise, in an analog-to-digital converter (ADC) having sampling switches on each of two input lines to the ADC, N double-sided and M single-sided switched capacitors on each input line: sampling an input voltage by closing the sampling switches, opening the sampling switches and comparing voltage levels between the input lines, iteratively switching the double-sided switched capacitors between a reference voltage (Vref) and ground, and iteratively switching the single-sided switched capacitors between ground and voltages that may equal Vref/2.sup.x where x ranges from 0 to m1 and m is a number of single-sided switched capacitors per input line. A common mode offset of the ADC may be less than V.sub.ADC.sub._.sub.fs/128+V.sub.ADC.sub._.sub.fs/256+V.sub.ADC.sub._.sub.fs/512+V.sub.ADC.sub._.sub.fs/1024 when m equals 4 and where V.sub.ADC.sub._.sub.fs is the full-scale voltage of the ADC.

A switched-capacitor circuit comprising a differential operational amplifier and a feedback circuit is described. In some embodiments, the feedback circuit may be configured to provide a reference voltage that is insensitive to temperature and/or process variations. In some embodiments, the feedback circuit may be configured to mitigate the time delay associated with one or more capacitors of the switched-capacitor circuit. The switched-capacitor circuit may be controlled by a pair of control signals. During a first phase, one or more capacitors may be charged, or discharged, through an input signal. During a second phase, the electric charge of the one or more capacitors may be retained.