Abstract: The invention provides a digital background calibration system and method for a successive approximation analog-to-digital converter comprising a digital to analog converter (DAC) having a plurality of weighted capacitors to be calibrated; means for splitting each of said weighted capacitors into a plurality of sub-capacitors and at least one redundant capacitor; means for multiplying the voltage level of at least one of the sub-capacitors with a PN sequence; and means for calibrating the weighted capacitor from the multiplied sub-capacitor and the redundant capacitor.

Abstract: A comparator including a preamplifier amplifying a first signal and a second signal to produce a first amplified signal on a first output terminal and a second amplified signal on a second output terminal. The comparator also includes a capacitor, a clamp and a latch coupled in parallel to the first output terminal and the second output terminal of the preamplifier. A control circuit is coupled to the variable capacitor and the clamp and is configured to close the clamp during a first time period to cause the first amplified signal and the second amplified signal to bypass the capacitor and the latch, and open the clamp during a second time period following the first time period to cause the first amplified signal and the second amplified signal to be coupled to the capacitor and the latch. The capacitor filters the amplified signals, and the latch produces a digital output signal of the comparator based on the filtered signals.

Abstract: A method for converting an analog signal to a digital signal is provided. Initially, a digital representation of a portion of an analog signal is generated. Residue of the analog signal is then sampled at a sampling instant so as to generate a residue sample. A signal having a frequency that is proportional to the voltage of the residue sample is generated, and the signal is measured to generate coarse and fine measurements of the frequency. A digital representation of the residue sample from the coarse and fine measurements is then generated.

Abstract: This invention relates to Analog to Digital Converters (ADC) and, inter alia, to Time Interleaved ADCs and Successive Approximation Register (SAR) ADC's. In a conventional Time Interleaved ADC employing SAR ADC units, the input signal is processed through a track-and-hold circuit (T/H), and then through a buffer circuit, before the SAR ADC unit. There, by means of a comparator, the signal is compared with a Digital-to-Analog Converter (DAC) signal from the SAR logic. The buffer reduces the influence of capacitive loading and physical layout design on the SAR ADC input, but typically has a non-linear response and thus introduces distortion to the input signal. This can limit the ADC linearity, particularly for high-speed ADCs operating with low-supply voltages. An objective of the invention is to reduce or eliminate the effect of the buffer non-linearity. This is done in some embodiments by routing both the signals to the comparator through the same buffer circuit.

Abstract: The present disclosure includes systems and techniques relating to low power current-voltage mixed ADC architecture. In some implementations, an apparatus includes sample and hold circuitry, at least one ADC module configured to generate a first digital output based on a first analog input provided to the sample and hold circuitry, and current generation circuitry configured to modulate an analog output of the sample and hold circuitry to generate a residue output corresponding to the first analog input absent at least a portion corresponding to the first digital output, and to provide the residue output as a second analog input to further circuitry to generate a second digital output.

Abstract: An A/D conversion device includes an A/D conversion circuit that converts an inputted analog signal to digital data and outputs it, a digital signal correction unit that performs a correction process to the digital data and outputs a digital signal, and a phase compensation unit that performs phase compensation in accordance with a phase delay amount of the digital signal with respect to the analog signal generated in the A/D conversion circuit and the digital signal correction unit wherein the A/D conversion circuit comprises a pulse transit circuit, a transmit position detection structure, and a digital data creation structure, the delay characteristic of the digital data being identified from the inputted analog signal.

Abstract: An electronic apparatus, control method thereof, remote control apparatus that controls the electronic apparatus, and control method thereof. The remote control apparatus includes a communication unit which communicates with the electronic apparatus; a user input unit which receives a user button selection indicating an input button; a sensing unit which senses movement of the remote control apparatus; and a control unit which controls the communication unit to transmit information about the user button selection to perform a function corresponding to the input button if the remote control apparatus is in a button input mode, and to transmit information about the movement of the remote control apparatus to the electronic apparatus to control the electronic apparatus by the movement if the remote control apparatus is in a motion recognition mode. Accordingly, controlling a game or a multimedia content is easier, and the user is provided with a new and interesting experience.

Abstract: A two-step analog-digital converting circuit includes a comparator, an upper bit counter and a pulse residue conversion unit. The comparator is configured to compare a ramp signal and an input signal, and to output a resulting comparative signal. The upper bit counter is configured to receive the comparative signal and a clock signal, and to output upper bit values corresponding to a first time interval between a generation time point of the ramp signal and a first edge of the clock signal, the first edge of the clock signal immediately preceding a state transition time point of the comparative signal. The pulse residue conversion unit is configured to receive the comparative signal and the clock signal, and to output lower bit values corresponding to a second time interval between the first edge of the clock signal and the state transition time point of the comparative signal.

Abstract: An analog-to-digital converter (ADC) circuit comprising two time-interleaved successive approximation register (SAR) ADCs. Each of the two time-interleaved SAR ADCs comprises a first stage SAR sub-ADC, a residue amplifier, a second stage SAR sub-ADC and a digital error correction logic. The residue amplifier is shared between the time-interleaved paths, has a reduced gain and operates in sub-threshold to achieve power effective design.

Abstract: An analog-to-digital converter includes: a first latch row corresponding to a first stage; a second latch row corresponding to a second stage; and a digital processor for encoding output signals of the second latch row and generating a digital signal. The first latch row includes a plurality of first latches that receive an analog input signal and reference voltages and operate in synchronization with a first clock signal, and the second latch row includes: a plurality of second latches that receive outputs signals of the plurality of first latches and operate in synchronization with a second clock signal delayed from the first reference clock; and a plurality of third latches that receive output signals of two neighboring latches of the plurality of first latches and operate in synchronization with the second clock signal by means of an interpolation technique.

Abstract: An A/D conversion circuit includes a pulse transit circuit, first and second pulse transit position detection circuits, and a digital signal generation circuit. The first pulse transit position detection circuit detects a transit position of the pulse signal output from the pulse transit circuit and generates a logical signal according to the transit position. The second pulse transit position detection circuit detects the circling number of the pulse signal output from the pulse transit circuit and generates a logical signal according to the circling number. The digital signal generation circuit synthesizes the logical signals output from the first and second pulse transit position detection circuits and generates a digital signal according to a size of an analog signal VA.

Abstract: An analog to digital converter converts an input analog signal to a digital representation using successive approximation logic to generate a plurality of digital values approximating the analog signal. Evaluation logic evaluates each of the digital values by converting each of the digital values in a digital to analog converter (DAC) to a DAC analog signal and comparing the DAC analog signal to the input analog signal to determine a comparison result used by the successive approximation logic to generate a next one of the digital values. An evaluation time period for one or more bits of the digital representation is longer than for one or more other bits in the digital representation. The DAC includes a resistor ladder. Reference voltages of the DAC are increased for evaluation of the least significant bit (LSB) to obtain more accurate results without increasing a number of resistors.

Abstract: Various embodiments of methods and devices for reducing capacitor mismatch errors in a pipeline analog-to-digital converter (ADC) are disclosed, where in a pipeline element circuit and during a first phase, an input voltage provided by a sample-and-hold circuit is presented to first and second capacitors arranged in parallel in the pipeline element circuit. During a second phase, a second voltage corresponding to a second charge associated with the second capacitance is amplified and stored in the pipeline element circuit. During a third phase, the same input voltage of the first phase is again presented to the first and second capacitors, which are arranged in parallel in the pipeline element circuit. During a fourth phase a first voltage corresponding to the first charge is amplified and stored in the pipeline element circuit.

Abstract: A system for signal processing comprising a cyclic analog to digital converter structure having a first stage and a second stage, wherein the first stage is configured to receive an input signal to perform 1.5 bits/stage ADC and to generate a first stage output signal, and the second stage is configured to receive the first stage output signal and to perform fine offset tuning using a final conversion phase. The second stage further configured to perform 1.5 bits/stage ADC and to generate a second stage output that is fed back to the first stage to iteratively generate a next 1.5 bits, until (N?3) most significant bits of N bits of data are generated. A third stage configured to generate a three least significant bits of the N bits of data using a flash ADC sampling circuit that samples a residue signal at the output of the first stage.

Abstract: A singled-ended, successive approximation register analog-to-digital converter convert an analog input voltage to a digital representation comprising m upper order bits and a number of lower order bits. The SAR ADC comprises SAR logic, a resistive network, multiple switches, and first and second LSB capacitors. The switches also comprises two sets of switches coupled to the resistive network, each set of switches is configured to couple a selected tap to each of the first and second LSB capacitors. When determining the lower order bits, the SAR logic is configured to control the sets of switches to change the first and second taps from one cycle in which one of the lower order bits is determined to a next cycle in which the next of the lower order bits is determined so that the voltage of both taps changes by a decreasing amount with each succeeding bit being determined.

Abstract: The present inventive concept relates to an analog-digital converter. The analog-digital converter includes a clock generating unit generating a clock signal; a clock delay adjusting unit outputting one of a first clock signal to a Kth clock signal according to a control signal; a capacitive digital-analog converting unit outputting a difference between the analog signal and a reference signal; a comparison unit judging whether an output of the capacitive digital-analog converting unit is 0, a positive number, or a negative number, in response to an output of the clock delay adjusting unit; and an SAR logic unit transferring an output of the comparison unit to the capacitive digital-analog converting unit in response to an output of the clock delay adjusting unit and performing a successive approximation operation to output the N-bit digital signal.

Abstract: An analog-to-digital (A/D) converter circuit arranged for receiving an analog input signal and for outputting a digital representation of said analog input signal is described.

Abstract: A Sigma-Delta analog-to-digital converter (ADC) having a direct time filter (DTF) in the feed-back path of the Sigma-Delta loop of the ADC. A Sigma-Delta ADC having a modified DTF in the feed-back path of the Sigma-Delta loop of the ADC is also disclosed. The ADC may also include a noise reduction block that splits an incoming RF signal, samples one of the split signals with a primary ADC, corrects for gain and delay inaccuracies and inverts the signal, applies the inverted signal to a primary digital-to-analog converter (DAC), combines the output of the DAC with the second split signal, which is then applied to a difference ADC.

Abstract: A pipeline type A/D converter is capable of expanding an input range and increasing the number of bits of digital output signals, without increasing thermal noises or an open loop gain needed for an operational amplifier. The number of sample-hold capacitors is divided from M into N and the reference voltage is multiplied by N to increase the number of capacitors available to add to and subtract from the reference voltage. The input range is expanded and the number of bits of the digital output signals is increased. Because the analog signal is sampled by all the capacitors, thermal noise does not deteriorate. The open loop gain needed for the operational amplifier does not increase, since the ratio of the capacitors each used as a feedback element for amplifying the analog signal to the remaining capacitors is unchanged before and after the division of the capacitors.

Abstract: An analog-to-digital converter is provided and comprises a most significant bit (MSB) conversion module, a successive approximation register analog-to-digital converter (SAR ADC) module, and an operation module. The MSB conversion module receives an analog signal to be converted, and converts the analog signal to an MSB with M bits, and obtains a redundancy signal. The SAR ADC module is coupled to the MSB conversion module. The SAR ADC receives the redundancy signal and processes the redundancy signal to be a least significant bit (LSB) with N bits. The operation module is coupled to the MSB conversion module and the SAR ADC module. The operation module receives the MSB with the M bits and the LSB with the N bits and generates a first digital signal with (M+N) bits. Each of M and N is positive, and (M+N) is a positive integer.

Abstract: Provided is an analog digital converting device which consumes a low power and guarantees fast operation characteristic. The analog digital converting device includes a sub-ADC and a successive approximation ADC. The sub-ADC converts an external analog signal into a first digital signal by using first and second reference voltages. The successive approximation ADC comprises a plurality of bit streams, and converts the external analog signal into a second digital signal according to a successive approximation operation using the first and second reference voltages. The successive approximation ADC receives the first digital signal, and converts the second digital signal in a state where one of the first and second reference voltages has been applied to the bit streams based on the first digital signal.

Abstract: An integrated circuit that is capable of converting an analog signal to at least one digital signal is provided. The integrated circuit includes a first input end capable of receiving a first analog signal. A first set of 2n-1 inverters are capable of quantizing the first analog signal and outputting a first set of 2n-1 digital values. Each of the first set of 2n-1 digital values is either 0 or 1. A first adder is coupled with the first set of 2n-1 inverters. The first adder is capable of summing the first set of 2n-1 digital values, outputting a first integer value that is capable of corresponding to at least one digital signal.

Abstract: A processing system including a first processing module and a second processing module is disclosed. The first processing module transforms and amplifies a grounded signal to generate a first processed signal and transforms and amplifies a predetermined signal to generate a second processed signal. The second processing module transforms the first processed signal to a first digital code according to a first reference voltage group and transforms the second processed signal to a second digital code according to a second reference voltage group. The second processing module adjusts a third reference voltage group according to the first and the second digital codes, and during a normal mode, the second processing module generates a third digital code according to the adjusted third voltage group.

Abstract: There are provided an A/D conversion circuit in which a counter is made to be capable of performing counting at both edges of a clock, up/down count values can be switched while the up/down count values are held, and the duty of the counting operation is difficult to be distorted even with the both-edge counting, a solid-state image sensor, and a camera system. An ADC 15A is configured as an integrating-type A/D conversion circuit using a comparator 151 and a counter 152. The counter 152 has a function of switching a count mode from an up count to a down count and from a down count to an up count while a value is held, a function of performing counting at both rising and falling edges of an input clock CK at a frequency two times as high as that of the input clock, and a function of latching the input clock CK in accordance with an output signal of the comparator 151 and setting non-inverted or inverted data of the latched data to be data of an LSB.

Abstract: An uncalibrated converter element in an analog-digital converter may be replaced with two or more smaller elements having an effective total net value that is equal to that of the uncalibrated converter element. In an exemplary case where the element is capacitor, one or more of these smaller capacitors may be independently calibrated by switching the smaller capacitor between two voltages, such as a reference voltage and ground, and then calculating a difference of corresponding digital output codes generated by the backend ADC with previously calibrated capacitors associated with lesser significant bits. The total capacitance of the uncalibrated capacitor may be apportioned between the smaller capacitors so that the individual maximum charge contribution of each smaller capacitor to the converter output together with any expected manufacturing variance does not exceed the aggregated contribution of the previously calibrated capacitors.

Abstract: An SAR ADC includes a digital-to-analog converter, a first comparator that compares an input analog signal with a reference analog signal, a second comparator that compares an input analog signal with a reference analog signal, a selection circuit that selects one of comparison results of the first comparator and the second comparator, and a control circuit that changes the multibit digital signal sequentially based on the selected comparison result in a plurality of steps so that the reference analog signal becomes closer to the input analog signal, and the control circuit controls the selection circuit to select the comparison result of the first comparator up to an intermediate step on the way of the plurality of steps and to select the comparison result of the second comparator after the intermediate step, and changes the bit value of the multibit digital signal according to the non-binary algorithm.

Abstract: A circuit and method for providing a digital output indicative of the time at which an event occurred is disclosed. In one aspect, the circuit includes a fine timing circuit configured to determine in which sub-interval of a clock period the event occurred, and a correction circuit configured to correct an erroneous offset between a first and second clock signals in the fine timing circuit. The correction circuit includes a synch circuit configured to determine in which half of the clock period the event occurred so as to correct for erroneous offset in the fine timing circuit.

Abstract: The configurations and adjusting method of a subrange analog-to-digital converter (ADC) are provided. The provided subrange ADC includes a X.5-bit flash ADC, a Y-bit SAR ADC and a (X+Y)-bit segmented capacitive digital-to-analog converter (DAC).

Abstract: An analog-to-digital (A/D) converter includes: a coarse A/D converter configured to convert, when converting an analog input signal into an N-bit digital signal, the analog input signal into a high-order m-bit digital signal; a fine A/D converter configured to convert the analog input signal into a low-order n-bit (where n=N?m) digital signal based on a conversion result of the coarse A/D converter; and a track-and-hold (TH) circuit configured to sample the analog input signal, to supply a comparison voltage compared with a coarse reference voltage to the coarse A/D converter, and to supply a comparison voltage compared with a fine reference voltage based on a conversion result of the fine A/D converter to the fine A/D converter. The TH circuit is configured to share a sampling capacitor in a selective input path for the analog input signal, the coarse reference voltage, and the fine reference voltage.

Abstract: To decrease the burden of digital processing, provided is an AD conversion apparatus comprising a pattern generating section that, for each target bit specified one bit at a time moving downward in the output data, generates a pattern signal having a pulse width or number of pulses corresponding to a weighting of the target bit; an integrating section that integrates the pattern signals according to a judgment value for judging a value of the target bit each time a pattern signal is generated, and outputs a reference signal obtained by accumulating the integrated value of each pattern signal; a comparing section that, each time generation of a pattern signal is finished, compares the input signal to the reference signal; and an output section that outputs the output data to have values corresponding to the comparison results obtained after each generation of a pattern signal corresponding to a bit is finished.

Abstract: Embodiments of the present invention provide a hybrid analog to digital converter that may include a DAC coupled to a hybrid analog to digital converter input; an integrator having an input coupled to the hybrid analog to digital converter input and the DAC, and generating an integrator output; a comparator coupled to the integrator output and having a comparator output; a successive approximation register coupled to the comparator output; and a counter coupled to the comparator output to generate an hybrid analog to digital converter output. The hybrid analog to digital converter may be operable as a successive approximation register converter and a continuous time sigma delta converter.

Abstract: In an A/D converter, a ramp unit generates a reference signal that increases or decreases over time. A comparison unit starts a comparison process of comparing an analog signal to the reference signal at a timing related to input of the analog signal and ends the comparison process at a timing at which the reference signal satisfies a predetermined condition with respect to the analog signal. A VCO includes a plurality of delay units having the same configuration and starts a transition process at a timing related to the start of the comparison process. A count unit counts a clock from the VCO. A low-order latch unit latches a low-order logic state, which is a logic state of the plurality of delay units, at a first timing related to the end of the comparison process. A high-order latch unit latches a high-order logic state.

Abstract: A Complex Analog to Digital Converter System on Chip (CADC SoC) implemented into a microcircuit system is provided. A series of stagger clock signals can be fixed on either a rising or falling edge of the system clock and a plurality of A/D converters can be grouped by sets (i.e. odd and even) and assigned to odd or even stagger clocks. A complex I&Q data manager is provided for controlling the system. A clock management system is responsive to an external signal to select from a set of stagger clock settings, thereby improving anti-alias performance.

Abstract: Disclosed is a circuit for converting an analog input signal into a digital code (b1-bN), comprising a delay circuit adapted to generate a periodical signal having a delay as a function of the analog input signal value; and a quantization stage for converting the delayed periodical signal into the digital code. The circuit converts an analog voltage or current into the time-domain, thus facilitating the implementation of high-speed analog-to-digital converters into submicron technologies, in particular CMOS technologies. A method of converting an analog input signal into a digital code (b1-bN) is also disclosed.

Abstract: The present invention provides an analog-to-digital converter (ADC) circuit comprising two time-interleaved successive approximation register (SAR) ADCs. Each of the two time-interleaved SAR ADCs comprises a first stage SAR sub-ADC, a residue amplifier, a second stage SAR sub-ADC and a digital error correction logic.

Abstract: An analog-to-digital converter (ADC) and a receiver that includes the ADC is disclosed. The ADC includes a first filter configured to receive a signal in an I-signal path of the receiver and a second filter configured to receive a signal in a Q-signal path of the receiver. The ADC further includes a quantizer alternatingly in connection with the first and second filters, and at least one DAC alternatingly in connection with the first and second filters. Switches in the ADC are configured to alternate connection between an input of the quantizer and outputs of the first and second filters, and are also configured to alternate connection between an output of the at least one DAC and inputs of the first and second filters.

Abstract: In one embodiment, a second-order delta-sigma analog-to-digital converter (ADC) includes a second-order integrator adapted to second-order integrate a value at a first node, where the first node is coupled to an input of the ADC. The ADC also includes a comparator coupled to an output of the second-order integrator. The ADC further includes a digital-to-analog converter (DAC) coupled between an output of the comparator and the first node. The DAC is adapted to receive a digital output of the comparator and to generate a first charge or a second charge. The DAC includes a first charge pump adapted to produce the first charge and a second charge pump adapted to produce the second charge. The first and second charges are asymmetric.

Abstract: A current sensing circuit including a current sensing unit, a feedback control unit, and a digital output unit is provided. The current sensing unit senses a current and generates a pulse signal according to at least one reference signal and at least one feedback signal. The feedback control unit is coupled to the current sensing unit and generates the at least one feedback signal according to a clock signal and the pulse signal. The digital output unit is coupled to the current sensing unit and outputs a digital signal according to the pulse signal. The digital output unit counts an amount of pulses of the pulse signal in a predetermined time period to output the digital signal, wherein the amount of pulses is positively correlated with a value of the current.

Abstract: An analog to digital converter has an input circuit, a computation circuit, an initialization circuit, and an output circuit. The input circuit is for receiving an analog signal and has a pair of outputs. A computation circuit has a pair of inputs coupled to the pair of outputs. The computation circuit has an amplifier having a pair of complementary outputs (Outp, Outn). The initialization circuit is coupled to the complementary outputs and is for biasing the complementary outputs at a time prior to the computation circuit beginning a computation on the analog signal. The output circuit is coupled to the pair of complementary outputs and provides a digital signal.

Abstract: The configurations and adjusting method of a subrange analog-to-digital converter (ADC) are provided. The provided subrange ADC includes a X.5-bit flash ADC, a Y-bit SAR ADC and a (X+Y)-bit segmented capacitive digital-to-analog converter (DAC).

Abstract: An analog-to-digital converter includes a higher-order analog-to-digital converter that outputs a higher-order digital value, a first lower-order converter that converts a first residual signal into a first lower-order digital value, a second lower-order converter that converts a second residual signal into a second lower-order digital value, a calibrator that outputs first and second offset adjustment signals for respectively designating offset adjustment amounts in reversed polarity based on a difference between the first and second lower-order digital values, wherein the first and second lower-order converters set a conversion calibration value based on the first and second offset adjustment signals and calibrate the first and second lower-order digital values based on the conversion calibration value.

Abstract: Piecewise conversion of an analog input signal is performed utilizing a plurality of relatively lower bit resolution A/D conversions. The results of this piecewise conversion are interpreted to achieve a relatively higher bit resolution A/D conversion without sampling frequency penalty.

Abstract: In a system based on an analog-digital converter (ADC) having an analog input signal and at least one quantization threshold, the analog-digital converter (ADC) includes an arrangement for varying the at least one quantization threshold.

Abstract: Superconductor analog-to-digital converters (ADC) offer high sensitivity and large dynamic range. One approach to increasing the dynamic range further is with a subranging architecture, whereby the output of a coarse ADC is converted back to analog and subtracted from the input signal, and the residue signal fed to a fine ADC for generation of additional significant bits. This also requires a high-gain broadband linear amplifier, which is not generally available within superconductor technology. In a preferred embodiment, a distributed digital fluxon amplifier is presented, which also integrates the functions of integration, filtering, and flux subtraction. A subranging ADC design provides two ADCs connected with the fluxon amplifier and subtractor circuitry that would provide a dynamic range extension by about 30-35 dB.

Abstract: First and second track and hold stages track and store an input voltage for a sample of an analog input signal. A coarse reference ladder provides a plurality of coarse references. The coarse reference ladder includes a first coarse reference and a second coarse reference ladder. A coarse ADC performs a first comparison of the input voltage and the coarse references and outputs a coarse output based on the first comparison. A switch matrix includes switches and is configured to close a switch corresponding to a coarse reference based on the coarse output. A fine reference ladder provides fine references. A fine ADC performs a second comparison of the input voltage and the fine references and outputs a fine output based on the second comparison. Logic outputs a digital output for the sample of the analog input signal based on the coarse output and the fine output.

Abstract: The invention relates to high-resolution analog-digital converters using so-called folding differential amplifier structures composed of differential circuits (crossed differential pairs) and of loads (cascode transistors). The folding structure according to the invention comprises, in the case where it is desired to produce four curves folded at two periods in the useful range of voltages to be converted, four folding blocks (one per curve). The first comprises 7 differential circuits and eight loads, the end loads not being linked to the output of the block. The other blocks comprise 6 differential circuits and eight loads, the last load of each block not being linked to the output of this block. Gains are achieved in terms of bulk, consumption and operating speed, with respect to existing structures.

Abstract: An analog to digital converter (ADC) can include a multi-input comparison unit configured to compare a pixel voltage from an image sensor, a comparison voltage comprising a stepped voltage modified during a coarse mode of operation, and a ramp voltage comprising a ramped voltage modified to one another during a fine mode of operation, to provide a comparison result signal that indicates whether the comparison voltage combined with the ramp voltage is greater than or less than the pixel voltage. A selection control signal generation unit can receive the comparison result signal and a mode control signal, to indicate the coarse or fine mode, to provide a selection control signal allowing modification of the comparison voltage in the coarse mode and to hold the comparison voltage constant in the fine mode. A reference voltage selection unit can receive the selection control signal to control modification of the comparison voltage.

Abstract: Feedback circuits with DC offset cancellation are described. In an exemplary design, a feedback circuit includes a slow integrator and a summer. The slow integrator receives a first intermediate signal at a particular point in the feedback circuit and provides a second intermediate signal. The summer is located after the particular point and receives and sums the first and second intermediate signals to reduce DC offset in the first intermediate signal. In one design, the feedback circuit may be a delta-sigma (??) modulator with at least one integrator coupled in cascade. The slow integrator is coupled to the output of the last integrator, receives the first intermediate signal from the last integrator, and provides the second intermediate signal. The summer is coupled to the last integrator and the slow integrator and sums the first and second intermediate signals to reduce DC offset in the first intermediate signal.

Abstract: An analog-to-digital converter includes a comparison signal generation unit and a control unit. The comparison signal generation unit determines a logic level of a comparison signal by comparing an input signal with a selected reference signal based on a switch control signal in a first comparison mode, and by comparing a difference voltage with a ramp signal based on the switch control signal in a second comparison mode. The difference voltage is generated based on the input signal and the selected reference signal such that a level of the difference voltage is lower than a fine voltage level corresponding to a voltage level of the selected reference signal in the second comparison mode. The control unit generates the switch control signal based on the comparison signal and a mode selection signal.

Abstract: With Successive Approximation Register (SAR) analog-to-digital converters (ADCs), there are several different architectures. One of these architectures is a “convert and shut down” architecture, where an internal amplifier is powered down during the sampling phase to reduce power consumption. This powering down comes at a price in that a portion of the convert phase is lost waiting for the amplifier to be powered back up. Here, an apparatus is provided that makes use of the entire convert phase by coarsely resolving a few bits during the period in which the amplifier is powering up to have an increased resolution over conventional SAR ADCs with “convert and shut down” architecture, while maintaining low power consumption.