Patent application number | Description | Published |
20100142653 | A/D CONVERSION APPARATUS, A/D CONVERSION METHOD, AND COMMUNICATION APPARATUS - An A/D conversion apparatus includes: a first and a second D/A converter to sample an analog signal and successively compare the analog signal and a reference signal to generate a first and a second comparison signal respectively; a first comparator to compare the first comparison signal generated by the first D/A converter with a benchmark signal; a second comparator to compare the second comparison signal generated by the second D/A converter with the benchmark signal; and a converter to convert the analog signal to a digital signal according to results of the comparisons by the first and second comparators. | 06-10-2010 |
20100150270 | SIGNAL PROCESSING CIRCUIT AND RECEIVER USING THE SAME - A signal processing circuit includes a decimation filter which down-samples over-sampled first three-phase digital signals to obtain second three-phase digital signals, and a converter which subjects the second three-phase digital signals to a three-phase to IQ conversion, and obtains orthogonal digital signals. | 06-17-2010 |
20100156683 | AMPLIFIER CIRCUIT AND A/D CONVERTER - An amplifier circuit includes a current source that is connected between a power supply voltage and an output node and that is turned on when a switching control signal takes a first value and is turned off when the switching control signal takes a second value; a grounded voltage control current source whose amount of current is controlled by an input voltage; a cascode transistor connected between the voltage control current source and the output node; a boost amplifier connected between a gate electrode and a source electrode of the cascode transistor; and a switch that is connected between an output node of the boost amplifier and a bias voltage and that is turned on for a predetermined period of time when a value of the switching control signal is switched from the second value to the first value, to forcefully rise the boost amplifier. | 06-24-2010 |
20120056770 | SUCCESSIVE APPROXIMATION REGISTER-ANALOG DIGITAL CONVERTER AND RECEIVER - An SAR-ADC includes input and reference terminals, first and second capacitor sets, a dummy capacitor, a comparator, a switch, and a logic. The first and second capacitor sets include first and second capacitors, respectively. The first capacitor has a first capacitance. The second capacitor has a second capacitance. The dummy capacitor has a third capacitance. The comparator compares an output voltage with a ground voltage and outputs a digital output code in accordance with a difference between the output and ground voltages. The switch is connected among the first capacitors of the first and second capacitor sets, and the reference terminal. The logic turns the switch based on the digital output code. The input terminal is located between the first and second capacitors of the first capacitor set. The second capacitor of the first capacitor set is located between the first and second capacitors of the second capacitor set. | 03-08-2012 |
20120133346 | SUCCESSIVE APPROXIMATION REGISTER A/D CONVERTER AND DC/DC CONVERTER - The SAR control circuit of the successive approximation register A/D converter changes the digital value by the first conversion frequency in a first conversion range according to the comparison result signal, and outputs the digital value. | 05-31-2012 |
20120303689 | ARITHMETIC CIRCUIT AND A/D CONVERTER - An arithmetic circuit includes: an input terminal for receiving an input signal; plural capacitors; and an amplifier circuit including an amplifying input terminal and an output terminal and configured to amplify a signal input from the amplifying input terminal and output it as an output signal from the output terminal. A first switch circuit becomes conductive based on a first control signal and connects the plural capacitors in parallel between the input terminal and a first voltage terminal for supplying a first voltage. A second switch circuit becomes conductive based on a second control signal and connects a first capacitor of the plural capacitors between the amplifying input terminal and a second voltage terminal for supplying a second voltage to form a first current path and a second capacitor of the plural capacitors between the amplifying input terminal and the output terminal to form a second current path. | 11-29-2012 |
20130015996 | AD CONVERTER AND INFORMATION PROCESSING APPARATUSAANM FURUTA; MasanoriAACI Odawara-shiAACO JPAAGP FURUTA; Masanori Odawara-shi JP - An analog-to-digital converter includes: weighted capacitors connected to each other at one ends thereof, having a capacitance value weighted at a predetermined ratio, and including a variable capacitance capacitor capable of reducing the capacitance value; a comparator including an input to which the one ends of the weighted capacitors are coupled; switches that connect the other ends different from the one ends to any of an input terminal into which an input signal is input, a reference voltage source used for successive approximation of the input signal, a ground, and an open terminal; a successive approximation controller that controls the switches to sample the input signal onto the weighted capacitors, and use the reference voltage source to generate a comparative voltage for the successive approximation, to thereby execute a successive approximation; and a capacitance controller that controls the switches to reduce a capacitance value of the variable capacitance capacitor. | 01-17-2013 |
20130049713 | A/D CONVERSION APPARATUS AND DC-DC CONVERSION APPARATUS - There is provided with an A/D conversion apparatus which the first terminal receives a reference voltage signal, the single-ended to differential converter conducts single-ended to differential conversion on the reference voltage signal to obtain a first differential signal, the A/D converter conducts A/D conversion on the first differential signal based on the reference voltage signal to obtain a first digital signal, the digital circuit detects a DC offset which is a difference between the first digital signal and a digital signal, the second terminal receives an input signal, the single-ended to differential converter conducts single-ended to differential conversion on the input signal to acquire a second differential signal, the A/D converter conducts A/D conversion on the second differential signal based on the reference voltage signal to acquire a second digital signal, and the digital circuit subtracts the DC offset from the second digital signal to obtain a third digital signal. | 02-28-2013 |
20130076544 | ANALOGUE TO DIGITAL CONVERTER AND SIGNAL PROCESSING SYSTEM - According to one embodiment, an analogue to digital converter converts an analogue input signal to a digital output signal. The converter includes an analogue to digital converting unit, a multiplexer, a pseudo-alias signal generator, a gain controller, and an alias signal compensator. The analogue to digital converting unit converts the analogue input signal to a plurality of digital signals. The multiplexer sequentially selects one of the digital signals and outputs the selected digital signal as a multiplexer output. The pseudo-alias signal generator generates a plurality of pseudo-alias signals from the digital signals. The pseudo-alias signal simulates an alias signal component in the multiplexer output. The gain controller generates a plurality of gain control signals by using the pseudo-alias signals. The gain control signal controls gain of the digital output signal. The alias signal compensator compensates the alias signal component by using the gain control signals. | 03-28-2013 |
20130076545 | TIME ERROR ESTIMATING DEVICE, ERROR CORRECTION DEVICE AND A/D CONVERTER - A time error estimating device for estimating a sampling time error of each of a plurality of sampling circuits when the sampling circuits generates a plurality of sampling output signals by performing sampling at timings shifted from one another has correlators each configured to obtain a correlation value representing a similarity between the sampling output signals, and a weight adder configured to estimate the sampling time error of the sampling circuits, based on a result obtained by adjusting a weight on the correlation value. | 03-28-2013 |
20130182803 | ANALOG-DIGITAL CONVERTER AND RECEIVER - According to an embodiment, there are provided a capacitor DAC for generating an output signal in accordance with a connection state of a capacitor element, a reference voltage generation circuit for supplying a reference voltage to the capacitor DAC, a comparator for outputting a comparison result in accordance with the output signal, a successive approximation register for outputting a digital signal in accordance with the comparison result, and a control circuit for controlling a connection state of the capacitor element in accordance with the comparison result and comparing an ideal code with a digital signal obtained by sampling a predetermined voltage, thereby correcting an error of the digital signal. | 07-18-2013 |
20130183920 | RESIDUAL SIGNAL GENERATING CIRCUIT, SUCCESSIVE APPROXIMATION AD CONVERTER, PIPELINED AD CONVERTER, AND RADIO RECEIVER - 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 2 | 07-18-2013 |
20140045444 | SIGNAL SAMPLING CIRCUIT AND RADIO RECEIVER - According to some embodiments, there is provided a signal sampling circuit in which the first sampling capacitor is connected to the first sampling switch, the second sampling capacitor is connected to the second sampling switch, the amplifier outputs a positive-side amplified signal by amplifying a signal input to the positive-side input terminal thereof and outputs a negative-side amplified signal by amplifying a signal input to the negative-side input terminal thereof, the first chopper switch is connected to the first sampling capacitor and the positive-side input terminal, the second chopper switch is connected to the first sampling capacitor and the negative-side input terminal, the third chopper switch is connected to the second sampling capacitor and the positive-side input terminal and the fourth chopper switch is connected to the second sampling capacitor and the negative-side input terminal. | 02-13-2014 |
20140361917 | COMPARING CIRCUIT AND A/D CONVERTER - The first amplifier operates according a first clock, changes voltages of a first terminal and a second terminal from a first fixed voltage to a second fixed voltage according to a voltage of an input signal and a first reference voltage, respectively, when an on period of a first clock starts, and keeps the voltages of the first and second terminals at the second fixed voltage, respectively, after the voltages of the first and second terminals reach the second fixed voltage and until the on period of the first clock ends, and the first comparator generates first and second logic signals that have logical levels different from each other, based on a difference between the voltages of the first and second terminals when the on period of a second clock whose on period at least partially overlaps with that of the first clock starts. | 12-11-2014 |