Patents by Inventor Fukashi Morishita
Fukashi Morishita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 12126352Abstract: A semiconductor device includes a digital-analog converter provided with a plurality of current cells, and a test circuit electrically connected to the digital-analog converter to test the digital-analog converter. The test circuit includes: a charge information holding circuit that holds, as differential charge information, a difference value between a first charge according to a first current and a second charge according to a second current by at least one or more current cells among the plurality of current cells; a reference voltage generation circuit that generates a reference voltage to be comparative object; and a comparison circuit that compares a determination voltage according to the differential charge information and the reference voltage to output a comparison result.Type: GrantFiled: November 1, 2022Date of Patent: October 22, 2024Assignee: Renesas Electronics CorporationInventors: Wataru Saito, Fukashi Morishita
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Publication number: 20240267068Abstract: The circuit area of the semiconductor device in which the transmission period and the reception period are alternately repeated is reduced. The semiconductor device includes a transmission circuit and a receiving circuit. The receiving circuit includes a gain control circuit that samples the input signal to adjust the gain of the receiving circuit during the reception period and adjusts the gain based on the sampling result during the transmission period.Type: ApplicationFiled: December 27, 2023Publication date: August 8, 2024Inventors: Wataru SAITO, Fukashi MORISHITA
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Patent number: 12040813Abstract: An integrating Analog-to-digital converter has a global counter that outputs a counter code signal including a multiphase signal. It also has a column circuit including: a ramp wave generation circuit outputting a ramp wave voltage; a comparator comparing the ramp wave voltage with a pixel voltage; and a latch circuit latching the counter code signal at output inversion timing of the comparator. An output value of the latch circuit is used as a digital conversion output value per the column circuit. The counter has a phase division circuit outputting, as an LSB of the digital conversion output value of the integrating analog-to-digital converter, a phase division signal to the latch circuit, the phase division signal dividing a phase of the counter code signal. The phase division circuit is arranged to a plurality of column circuits, and the LSB is shared by a plurality of phase division circuits.Type: GrantFiled: August 11, 2022Date of Patent: July 16, 2024Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yoichi Iizuka, Fukashi Morishita
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Publication number: 20240171835Abstract: A programmable gain amplifier provided in a semiconductor device includes a fully differential amplifier configured to amplify differential input voltages having an offset voltage. First and second correction voltages are input to a non-inverting input node and an inverting input node of the fully differential amplifier via first and second resistance elements, respectively.Type: ApplicationFiled: October 31, 2023Publication date: May 23, 2024Applicant: Renesas Electronics CorporationInventors: Wataru SAITO, Fukashi MORISHITA
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Publication number: 20240151804Abstract: A circuit including a first circuit, a second circuit and a controller is provided, the first circuit and the second circuit each including a sample-and-hold circuit configured to hold a level of an input signal of a specific timing and an analog-to-digital converter circuit configured to convert the level of the input signal held in the sample-and-hold circuit into digital data and to output the digital data, the controller being configured to cause the first circuit to output the level of the input signal of a first timing and to cause the second circuit to output the level of the input signal of a second timing.Type: ApplicationFiled: October 6, 2023Publication date: May 9, 2024Applicant: Renesas Electronics CorporationInventors: Norihito KATOU, Fukashi MORISHITA
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Patent number: 11968465Abstract: A technique capable of improving linearity at a low illuminance is provided. A solid-state sensing image device includes: a pixel array including a plurality pixels arranged in a matrix form and a plurality of pixel signal lines connected to the plurality of pixels and receiving pixel signals supplied from the plurality pixels; a column-parallel A/D converting circuit connected to the plurality of pixel signal lines; and a reference-voltage generating circuit generating ramp-wave reference voltage that linearly changes in accordance with time passage. The column-parallel A/D converting circuit includes a first A/D converter, the first A/D converter includes: a first input terminal connected to the pixel signal line; a second input terminal receiving the reference voltage; and an offset generating circuit connected to the first input terminal and generating an offset voltage for the first input terminal.Type: GrantFiled: June 15, 2022Date of Patent: April 23, 2024Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Norihito Katou, Fukashi Morishita
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Publication number: 20230412947Abstract: A solid-state image sensor includes a buffer circuit, and an AD conversion circuit. The buffer circuit is connected to a first pixel and a second pixel of a plurality of pixels. The AD conversion circuit converts a voltage signal from the buffer circuit into a digital signal. The buffer circuit includes a voltage holding circuit connected to the first pixel, a voltage holding circuit connected to the second pixel, and a switch circuit. The switch circuit selectively switches the voltage holding circuit which outputs a voltage signal to the AD conversion circuit between the voltage holding circuits. The buffer circuit carries out an operation of holding a voltage signal of the first pixel in the voltage holding circuit and an operation of holding a voltage signal of the second pixel in the voltage holding circuit in parallel with each other.Type: ApplicationFiled: May 17, 2023Publication date: December 21, 2023Inventors: Yoichi IIZUKA, Fukashi MORISHITA
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Patent number: 11800254Abstract: An image sensor including an ADC circuit receiving pixel data to be supplied in parallel from the a pixel array, outputting a reference signal in accordance with a digital code, comparing the reference signal and the pixel data, and outputting the digital code at which the reference signal and the pixel data have a predetermined relation, the ADC circuit including a ramp-signal generating circuit outputting a ramp signal having a gradient with respect to change of the digital code, the gradient being different between when the digital code is in a first range and when the digital code is in a second range different from the first range and an attenuator receiving the ramp signal to be supplied and outputting the reference signal having a gradient being the same between when the digital code is in the first range and when the digital code is in the second range.Type: GrantFiled: June 27, 2022Date of Patent: October 24, 2023Assignee: Renesas Electronics CorporationInventor: Fukashi Morishita
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Publication number: 20230138391Abstract: A semiconductor device includes a digital-analog converter provided with a plurality of current cells, and a test circuit electrically connected to the digital-analog converter to test the digital-analog converter. The test circuit includes: a charge information holding circuit that holds, as differential charge information, a difference value between a first charge according to a first current and a second charge according to a second current by at least one or more current cells among the plurality of current cells; a reference voltage generation circuit that generates a reference voltage to be comparative object; and a comparison circuit that compares a determination voltage according to the differential charge information and the reference voltage to output a comparison result.Type: ApplicationFiled: November 1, 2022Publication date: May 4, 2023Applicant: Renesas Electronics CorporationInventors: Wataru SAITO, Fukashi MORISHITA
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Publication number: 20230087101Abstract: An integrating Analog-to-digital converter has a global counter that outputs a counter code signal including a multiphase signal. It also has a column circuit including: a ramp wave generation circuit outputting a ramp wave voltage; a comparator comparing the ramp wave voltage with a pixel voltage; and a latch circuit latching the counter code signal at output inversion timing of the comparator. An output value of the latch circuit is used as a digital conversion output value per the column circuit. The counter has a phase division circuit outputting, as an LSB of the digital conversion output value of the integrating analog-to-digital converter, a phase division signal to the latch circuit, the phase division signal dividing a phase of the counter code signal. The phase division circuit is arranged to a plurality of column circuits, and the LSB is shared by a plurality of phase division circuits.Type: ApplicationFiled: August 11, 2022Publication date: March 23, 2023Inventors: Yoichi IIZUKA, Fukashi MORISHITA
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Publication number: 20230022468Abstract: An image sensor including an ADC circuit receiving pixel data to be supplied in parallel from the a pixel array, outputting a reference signal in accordance with a digital code, comparing the reference signal and the pixel data, and outputting the digital code at which the reference signal and the pixel data have a predetermined relation, the ADC circuit including a ramp-signal generating circuit outputting a ramp signal having a gradient with respect to change of the digital code, the gradient being different between when the digital code is in a first range and when the digital code is in a second range different from the first range and an attenuator receiving the ramp signal to be supplied and outputting the reference signal having a gradient being the same between when the digital code is in the first range and when the digital code is in the second range.Type: ApplicationFiled: June 27, 2022Publication date: January 26, 2023Applicant: Renesas Electronics Corporation.Inventor: Fukashi MORISHITA
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Publication number: 20220408046Abstract: A technique capable of improving linearity at a low illuminance is provided. A solid-state sensing image device includes: a pixel array including a plurality pixels arranged in a matrix form and a plurality of pixel signal lines connected to the plurality of pixels and receiving pixel signals supplied from the plurality pixels; a column-parallel A/D converting circuit connected to the plurality of pixel signal lines; and a reference-voltage generating circuit generating ramp-wave reference voltage that linearly changes in accordance with time passage. The column-parallel A/D converting circuit includes a first A/D converter, the first A/D converter includes: a first input terminal connected to the pixel signal line; a second input terminal receiving the reference voltage; and an offset generating circuit connected to the first input terminal and generating an offset voltage for the first input terminal.Type: ApplicationFiled: June 15, 2022Publication date: December 22, 2022Inventors: Norihito KATOU, Fukashi MORISHITA
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Patent number: 11528441Abstract: It is an object of the present invention to provide a technique for reducing the variation of a bias voltage. An analog-to-digital converter comprises a comparator including a first amplifier and a second amplifier inputted one output of the first amplifier. The first amplifier is a differential type of amplifier, and includes one input terminal for receiving a signal and the other input terminal for receiving a reference signal which changes with a predetermined slope. The second amplifier is a single-ended type amplifier, and determines an auto zero voltage based on the amplified voltage by an auto zero operation of the first amplifier and includes a self-bias circuit using the auto zero voltage as a bias voltage. The comparator is plural, the comparators are plurality which arranged in a row direction, and outputs a digital value based on an analog voltage inputted to the other input terminal in parallel operation.Type: GrantFiled: December 2, 2021Date of Patent: December 13, 2022Assignee: RENESAS ELECTRONICS CORPORATIONInventor: Fukashi Morishita
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Patent number: 11516421Abstract: A solid-state imaging device capable of suppressing variations in reference voltages and improving performance of reference voltages is provided. According to one embodiment, the solid-state imaging device includes a pixel outputting a luminance signal voltage corresponding to an amount of incident light, reference voltages, a reference voltage generation circuit outputting a ramp signal and an inverse ramp signal, and an AD converter, and the AD converter includes a comparator including an amplifier coupled to one input terminal, a reference voltage and an input terminal coupled to each of the ramp signals via a capacitor, and an input terminal coupled to each of the reference voltage and the ramp signal via a capacitor, and a ramp current cancel circuit coupled to each of the reference voltages via a cancel capacitor.Type: GrantFiled: January 8, 2020Date of Patent: November 29, 2022Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Osamu Matsumoto, Masanori Otsuka, Fukashi Morishita
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Publication number: 20220210364Abstract: It is an object of the present invention to provide a technique for reducing the variation of a bias voltage. An analog-to-digital converter comprises a comparator including a first amplifier and a second amplifier inputted one output of the first amplifier. The first amplifier is a differential type of amplifier, and includes one input terminal for receiving a signal and the other input terminal for receiving a reference signal which changes with a predetermined slope. The second amplifier is a single-ended type amplifier, and determines an auto zero voltage based on the amplified voltage by an auto zero operation of the first amplifier and includes a self-bias circuit using the auto zero voltage as a bias voltage. The comparator is plural, the comparators are plurality which arranged in a row direction, and outputs a digital value based on an analog voltage inputted to the other input terminal in parallel operation.Type: ApplicationFiled: December 2, 2021Publication date: June 30, 2022Inventor: Fukashi MORISHITA
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Patent number: 11115614Abstract: The present invention provides a semiconductor device having an integration type A/D converter capable of speeding up. The semiconductor device includes a Johnson counter 18 for transmitting a lower bit counter signal JC<3:0>, a lower bit latch circuit 11 for outputting a lower bit latch result signal by a lower bit counter signal JC<3:0> and a lower bit latch signal 14, a determination circuit 12 for outputting an upper bit latch signal 15 by a lower bit latch signal 14, a binary gray converter circuit 20 for transmitting an upper bit counter signal GR<n:3>, and an upper bit latch circuit 13 for outputting an upper bit latch result signal by an upper bit counter signal GR<n:3> and an upper bit latch signal 15.Type: GrantFiled: October 30, 2019Date of Patent: September 7, 2021Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yoichi Iizuka, Fukashi Morishita
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Publication number: 20200244908Abstract: A solid-state imaging device capable of suppressing variations in reference voltages and improving performance of reference voltages is provided. According to one embodiment, the solid-state imaging device includes a pixel outputting a luminance signal voltage corresponding to an amount of incident light, reference voltages, a reference voltage generation circuit outputting a ramp signal and an inverse ramp signal, and an AD converter, and the AD converter includes a comparator including an amplifier coupled to one input terminal, a reference voltage and an input terminal coupled to each of the ramp signals via a capacitor, and an input terminal coupled to each of the reference voltage and the ramp signal via a capacitor, and a ramp current cancel circuit coupled to each of the reference voltages via a cancel capacitor.Type: ApplicationFiled: January 8, 2020Publication date: July 30, 2020Inventors: Osamu MATSUMOTO, Masanori OTSUKA, Fukashi MORISHITA
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Publication number: 20200195871Abstract: The present invention provides a semiconductor device having an integration type A/D converter capable of speeding up. The semiconductor device includes a Johnson counter 18 for transmitting a lower bit counter signal JC<3:0>, a lower bit latch circuit 11 for outputting a lower bit latch result signal by a lower bit counter signal JC<3:0> and a lower bit latch signal 14, a determination circuit 12 for outputting an upper bit latch signal 15 by a lower bit latch signal 14, a binary gray converter circuit 20 for transmitting an upper bit counter signal GR<n:3>, and an upper bit latch circuit 13 for outputting an upper bit latch result signal by an upper bit counter signal GR<n:3> and an upper bit latch signal 15.Type: ApplicationFiled: October 30, 2019Publication date: June 18, 2020Inventors: Yoichi IIZUKA, Fukashi MORISHITA
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Patent number: 10321086Abstract: A semiconductor device includes a pixel array including a plurality of pixels arranged in a matrix, each pixel including a first switch and a second switch, a scanning circuit, in a first mode, enabling a first signal to be output from the pixel by setting the first and second switches to “off” in a period before a first timing, enabling a second signal to be output from the pixel by setting only the first switch to “on” for a predetermined period from the first timing, and enabling a third signal to be output from the pixel by setting the first and second switches to “on” for a predetermined period from a second timing after the first timing, and a first AD (Analog/Digital) converter, in a second mode, capable of performing AD conversion by comparing the difference between the second signal and the first signal with a reference signal.Type: GrantFiled: September 14, 2017Date of Patent: June 11, 2019Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Kazuhiro Ueda, Fukashi Morishita
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Patent number: 10257457Abstract: Provided is a solid-state imaging device capable of increasing the speed of an A/D converter. The solid-state imaging device includes a successive approximation A/D converter that performs A/D conversion on an analog pixel signal. The successive approximation A/D converter includes a D/A converter, a comparator, and a successive approximation register. The D/A converter converts a digital reference signal to an analog reference signal. The successive approximation register operates based on the result of comparison by the comparator to generate the digital reference signal in such a manner that the analog reference signal approximates the analog pixel signal. The D/A converter includes a split capacitor, first capacitors, second capacitors, a switch array, a third capacitor, and a multiplexer. The first capacitors each have a first electrode coupled to the output node. The second capacitors are coupled to a second electrode of the split capacitor.Type: GrantFiled: October 30, 2017Date of Patent: April 9, 2019Assignee: Renesas Electronics CorporationInventors: Osamu Matsumoto, Fukashi Morishita