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Kazuo Matsukawa, Osaka JP

Kazuo Matsukawa, Osaka JP

Patent application numberDescriptionPublished
20090040089A-TO-D CONVERTER - A successive approximation type A-to-D converter includes a cyclic D-to-A converter (02-12-2009
20090128382SEMICONDUCTOR DEVICE, SEMICONDUCTOR DEVICE TESTING APPARATUS, AND SEMICONDUCTOR DEVICE TESTING METHOD - In a pass/fail judgment test for a semiconductor IC having plural DACs, there is a problem that the test time is undesirably increased due to an increase on the number of DACs or an increase in resolution.05-21-2009
20100085228SEMICONDUCTOR DEVICE HAVING AE MODULATOR, AND SEMICONDUCTOR SYSTEM - A semiconductor device comprises an overflow detection circuit (04-08-2010
20100149010PIPELINED AD CONVERTER - A pipelined AD converter (06-17-2010
20100182181A-TO-D CONVERTER - A successive approximation type A-to-D converter includes a cyclic D-to-A converter (07-22-2010
20110018752FLASH A/D CONVERTER, FLASH A/D CONVERSION MODULE, AND DELTA-SIGMA A/D CONVERTER - In a flash A/D converter, a predictor predicts next analog input data based on a digital output signal from an A/D converter, and outputs prediction data. Based on the prediction data from the predictor, a controller turns on comparators having reference voltages near the prediction data, and in order to ensure a certain degree of A/D conversion accuracy even when the prediction fails, also turns on even-numbered comparators 01-27-2011
20110050476INTEGRATOR, RESONATOR, AND OVERSAMPLING A/D CONVERTER - An integrator includes an operational amplifier, a first filter connected to an inverting input terminal of the operational amplifier, and a second filter connected between the inverting input terminal and an output terminal of the operational amplifier. The first filter includes n resistive elements connected in series, and (n−1) capacitive elements each having one end connected to an interconnecting node of the resistive elements and the other end connected to ground. The second filter includes n capacitive elements connected in series, and (n−1) resistive elements each having one end connected to an interconnecting node of the capacitive elements and the other end connected to ground.03-03-2011
20110133964OVERSAMPLING A/D CONVERTER - An oversampling A/D converter includes a first filter including a first resistive element, a first capacitive element, a second resistive element, an operational amplifier, and a second capacitive element; a second filter receiving an output of the first filter; a third filter including a third resistive element, a third capacitive element, and a fourth resistive element; a quantizer receiving an output of the third filter and generating a digital signal; and a D/A converter converting the digital signal to an analog current signal. The D/A converter inputs the generated analog current signal to an inverting input terminal of the operational amplifier.06-09-2011
20110169677RESONATOR AND OVERSAMPLING A/D CONVERTER - Two resistive elements and a capacitive element are coupled between a first node and each of an inverting input terminal of an operational amplifier, an output terminal of the operational amplifier, and a common node. A resistive element and a capacitive element are coupled between the first node and a signal input terminal. Two capacitive elements and a resistive element are coupled between a second node and each of the inverting input terminal, the output terminal, and the common node. Two capacitive elements are coupled between the second node and each of the signal input terminal, and the common node.07-14-2011
20110200077DELTA-SIGMA MODULATOR AND WIRELESS COMMUNICATION DEVICE - In a DSM including a loop in which an output signal of a quantizer is digitally processed, and fed back through a DAC to an analog filter, the quantizer quantizes an analog signal from an analog filter section to output a digital signal. The digital signal from the quantizer is digitally processed in a first-order recursive filter circuit including a variable gain amplifier and a delay element. A LUT receives both the digital signal from the quantizer and a table control signal, which is an output signal from the recursive filter circuit, and stores in advance compensation values corresponding to the both signals. A compensation value from the LUT is used to provide a digital output signal compensated for a delay. The digital output signal is converted into an analog signal in the DAC, and then subtracted from an analog input signal in the analog filter section.08-18-2011
20110254718INTEGRATOR AND DELTA-SIGMA MODULATOR INCLUDING THE SAME - An integrator is provided which can reduce a disturbance in the current waveform of a current DA converter in order to improve the SNR of a ΔΣ modulator, for example. The integrator includes an operational amplifier, and feedback paths provided in parallel between the output terminal and inverting input terminal of the operational amplifier. In one of the feedback paths, an integrating capacitor and at least one resistor are connected in series. In the other feedback path, a second integrating capacitor whose capacitance value is smaller than that of the integrating capacitor is provided.10-20-2011
20120262320RESONATOR, DELTA-SIGMA MODULATOR, AND WIRELESS COMMUNICATION DEVICE - Two T filters, one of which includes two resistive elements and one capacitive element and the other of which includes two capacitive elements and one resistive element, are inserted in a negative-feedback section of an operational amplifier, and a resistive element and a capacitive element are connected between each of intermediate nodes and a signal input terminal. A resistive element and a capacitive element which are connected to each other in parallel are connected between the signal input terminal and an inverting input terminal of the operational amplifier. With this configuration, overall admittances where elements connected to the corresponding intermediate nodes are in parallel connection are equal to each other.10-18-2012
20120293346OFFSET CORRECTION DEVICE OF COMPARATOR - A comparator offset correction device opens an open switch 11-22-2012
20130169460DELTA-SIGMA MODULATOR, INTEGRATOR, AND WIRELESS COMMUNICATION DEVICE - A delta-sigma modulator includes: an integrator having an operational amplifier; a quantizer quantizing an output of the integrator; a first D-A converter converting an output of the quantizer to a current signal to provide negative feedback to the operational amplifier; a feedforward path feeding forward an input of the integrator to the quantizer; and a second D-A converter converting the output of the quantizer to a current signal to provide negative feedback to the quantizer. The integrator includes a resistive element having a first end connected to the input of the integrator and a second end connected to an inverting input of the operational amplifier, n capacitive circuits connected in series between the inverting input and an output of the operational amplifier, and (n−1) resistive elements each having a first end connected to an interconnecting node of the capacitive circuits and a second end connected to a common node.07-04-2013
20130194719CAPACITOR ARRAY AND SIGNAL PROCESSOR INCLUDING THE ARRAY - A capacitor array includes a plurality of comb capacitors sharing a common comb electrode. At least one of the comb capacitors has a comb electrode as a single base part. Each of the other ones of the comb capacitors has an electrode formed by coupling a plurality of base parts. In the other ones of the comb capacitors, a space between a wire coupling the base parts and an end of each of comb teeth of the common electrode, which is interposed between the base parts, is larger than a space between a base of each of the base parts of the plurality of comb capacitors and an end of each of the comb teeth of the common electrode, which is interposed between comb teeth of the base part.08-01-2013
20130249718OVERSAMPLING A/D CONVERTER - An oversampling A/D converter includes a first filter including a first resistive element, a first capacitive element, a second resistive element, an operational amplifier, and a second capacitive element; a second filter receiving an output of the first filter; a third filter including a third resistive element, a third capacitive element, and a fourth resistive element; a quantizer receiving an output of the third filter and generating a digital signal; and a D/A converter converting the digital signal to an analog current signal. The D/A converter inputs the generated analog current signal to an inverting input terminal of the operational amplifier.09-26-2013
20140055294RESONATOR AND OVERSAMPLING A/D CONVERTER - Two resistive elements and a capacitive element are coupled between a first node and each of an inverting input terminal of an operational amplifier, an output terminal of the operational amplifier, and a common node. A resistive element and a capacitive element are coupled between the first node and a signal input terminal. Two capacitive elements and a resistive element are coupled between a second node and each of the inverting input terminal, the output terminal, and the common node. Two capacitive elements are coupled between the second node and each of the signal input terminal, and the common node.02-27-2014
20140113575DELTA SIGMA MODULATOR, AS WELL AS RECEIVER DEVICE AND WIRELESS COMMUNICATION DEVICE PROVIDED WITH SAME - A delta sigma modulator includes a filter circuit including an integrator having an operational amplifier; a first addition circuit provided between an output section of the filter circuit and an input section of a quantizer, and including a first resistive element; and a second addition circuit including at least one of a first feedforward circuit including a second resistive element or a first feedback circuit configured to feed back, as an analog signal, a digital output signal having been quantized by the quantizer, to an input section of the quantizer, wherein at least one of the first addition circuit or the first feedback circuit includes a phase compensator.04-24-2014
20140266828RESONANT FILTER, DELTA-SIGMA A/D CONVERTER, AND SEMICONDUCTOR DEVICE - A delta-sigma A/D converter includes a loop filter including a resonant filter, a quantizer, and a feedback D/A converter. The resonant filter includes a resonator including a resistor and a capacitor, and a feedback path through which an output of the resonator is positively fed back to an input of the resonator. The resonant filter operates as an oscillator or a filter under the on/off control of a first switch. At least one of the resistor and the capacitor of the resonator is configured to allow a resistance value or a capacitance value thereof to be adjusted based on a third external signal.09-18-2014
20140285370SUCCESSIVE APPROXIMATION AD CONVERTER AND NOISE GENERATOR - In a successive approximation AD converter, a noise generator outputs the output of a ΔΣ modulator as a noise signal. A selector circuit can output the noise signal, in place of a digital signal for generating a comparison-target voltage for the next bit, to a capacitor element of a capacitance DAC. During sampling of an analog input voltage, the noise signal is supplied to the capacitance DAC via the selector circuit, and thereafter normal successive approximation operation is executed.09-25-2014
20140301253DEM CIRCUIT, DELTA-SIGMA MODULATOR, D/A CONVERTER, AND WIRELESS COMMUNICATION DEVICE - DEM circuit (10-09-2014

Patent applications by Kazuo Matsukawa, Osaka JP

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