Abstract:
Systems, apparatuses, and methods are provided for analog-to-digital converters (ADCs), such as successive-approximation-register (SAR) ADCs and pipelined ADCs that utilize distributed virtual-ground switching (DVS). DVS circuits and systems receive reference signal inputs that are provided to input signal buffers at the input side of the buffers via reference switches. The input signal buffers and corresponding switches are distributed into scaled replicas that each receive an analog input signal via input signal switches during a first operational phase and are connected to top plates of corresponding distributed capacitors. The bottom plates of the capacitors are sampled to provide analog input signal representations. Based on the value of the signal representations, a state machine controls each of the switches to apply reference signals to the input buffers, during a second operation phase, and to iteratively generate additional signal representations and provide a digital signal that corresponds to the analog input signal.
Abstract:
A circuit includes a track and hold (T/H) block to track an analog input signal during a track phase and to hold the analog input signal during a hold phase. A pipelined converter stage includes an analog to digital converter (ADC) receives the analog input signal from the T/H block and generates a digital output signal corresponding to the analog input signal. A digital to analog converter (DAC) element in the pipelined converter stage receives the digital output signal from the ADC and generates a current output signal representing an analog value for a portion of the analog input signal. A detector monitors the current output signal of the DAC element with respect to a predetermined reference current during the track phase and generates a trim signal if the current output signal is different from the predetermined reference current.
Abstract:
There is provided with a residual signal generating circuit in which the capacitive DA converter generates a first difference signal with respect to an input signal based on a criterion voltage, the criterion voltage being indicative of an input range of the input signal, the reference voltage generating circuit divides the criterion voltage to obtain at least one partial voltage signal, the residual signal generating section generates 2N−1 first residual signal according to a difference between the first difference signal and 2N−1−1 first reference signal, the 2N−1−1 first reference signal being 2N−1−1 partial voltage signal among said at least one partial voltage signal generated by the reference voltage generating circuit, the comparator compares the 2N−1 first residual signal with a fixed voltage to obtain 2N−1 first comparison signal each indicative of a logical value, and the decoder decodes the 2N−1 first comparison signal to obtain first data of N bits.
Abstract:
A switched capacitor circuit, which is operable in two or more kinds of operation modes including a first and second operation modes, includes an amplifier and two or more internal capacitors with switches for controlling connection/disconnection of the capacitor. In the first operation mode that precedes the second operation mode, the switched capacitor circuit generates the first analog output voltage by using the first internal capacitor connected between an input terminal and output terminal of the amplifier by using its switches, the other internal capacitances connected between an input terminal of the amplifier and each analog input voltage supply by using its switches. In the second operation mode, the switched capacitor circuit generates the second analog output voltage with larger feedback factor of the amplifier than it in the first operation mode, by removing some of the internal capacitors, except the first internal capacitor, from the first operation mode.
Abstract:
An AD converter includes: AD conversion stages configured to generate digital data having a value corresponding to a relationship between two analog signals being input and amplifying two analog residual signals with a first amplifier and a second amplifier with gain to be controlled to output the signals; and a gain control part configured to control gain of the first amplifier and the second amplifier on the basis of a monitoring result of the output signals of the first amplifier and the second amplifier. The first amplifier and the second amplifier are formed of open-loop amplifiers, and the gain control part takes out amplitude information of the output signals of the first amplifier and the second amplifier in at least one of the AD conversion stages and performs gain control so that amplitude of the analog signals being output from the stage converges on setting amplitude being set.
Abstract:
There is provided with a residual signal generating circuit in which the capacitive DA converter generates a first difference signal with respect to an input signal based on a criterion voltage, the criterion voltage being indicative of an input range of the input signal, the reference voltage generating circuit divides the criterion voltage to obtain at least one partial voltage signal, the residual signal generating section generates 2N−1 first residual signal according to a difference between the first difference signal and 2N−1−1 first reference signal, the 2N−1−1 first reference signal being 2N−1−1 partial voltage signal among said at least one partial voltage signal generated by the reference voltage generating circuit, the comparator compares the 2N−1 first residual signal with a fixed voltage to obtain 2N−1 first comparison signal each indicative of a logical value, and the decoder decodes the 2N−1 first comparison signal to obtain first data of N bits.
Abstract:
A pipelined analog-to-digital converter with less power consumption is provided. In one embodiment, the pipelined analog-to-digital converter comprises a first stage, a second stage, and a third stage. The first stage receives a first stage input signal to derive a first stage output signal and a first residue. The second stage receives a second stage input signal to derive a second stage output signal and a second residue, wherein the second stage input signal corresponds to the first residue. The third stage receives a third stage input signal to derive a third stage output signal and a third residue, wherein the third stage input signal corresponds to the second residue. The first, second and third stages share an operational amplifier by utilizing at least three phases to control the operational amplifier.
Abstract:
A stage of a pipelined analog-to-digital converter can include first and second pluralities of digital-to-analog converters (DACs), the first plurality sufficient in number to produce a residue from the stage, the second plurality having their outputs added into an analog output of the stage. A mapping circuit can exchange inputs between selected ones of the first and second pluralities of DACs, and a calibration circuit can provide first and second calibration signals to the selected one of the first plurality and another of the second plurality of DACs. The calibration signals can correlate to each other, but be uncorrelated to an analog input and digital output of the stage, and have unequal and partially offsetting effects on the stage's residue. A correction circuit can correct the digital output of the stage for circuit path errors based on a correlation between the calibration signals and an output of a succeeding stage.
Abstract:
An integrated circuit allows for the isolation of the input of an analog-to-digital converter (ADC) from a summing-node (SNS) algorithm. The integrated circuit contains a gating device that is controlled by bits of a flash analog-to-digital converter (ADC) to gate input samples to sub-ranges that are used by the SNS algorithm. A single sub-range is chosen to be used by the SNS algorithm.
Abstract:
An analog to digital converting device includes a first digital conversion (ADC) circuit configured to convert an inputted analog signal into a first digital signal, a first multiplying digital to analog converting (MDAC) circuit configured to amplify a difference between a first converted signal and the inputted analog signal, a second ADC circuit configured to convert an output of the first MDAC circuit into a second digital signal, a second MDAC circuit configured to amplify difference between a second converted signal converted from the second digital signal and the output of the first MDAC circuit, a third ADC circuit configured to convert an output of the second MDAC circuit into a third digital signal, and a common amplifying circuit shared by the first and the second MDAC circuits, wherein the common amplifying circuit consumes current based on which MDAC circuit the common amplifying circuit operates with.