Patents by Inventor Hajime Shibata
Hajime Shibata 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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Publication number: 20240080033Abstract: Continuous-time (CT) analog-to-digital converters (ADCs) implementing digital correction of digital-to-analog converter (DAC) errors are disclosed. In a CT pipeline stage of a CT ADC, a CT analog input signal is sent to two different paths. A first path (a “feedforward” path) includes a cascade of a sub-ADC and a sub-DAC. A second path (a “forward” path) includes an analog delay circuit to align the delays of the input signal in the feedforward and forward paths. A combiner subtracts the output of the analog delay of the forward path from the output of the sub-DAC in the feedforward path to generate a residue signal. Devices and methods disclosed herein are based on recognition that, if the errors introduced by the sub-DAC are known, they can be corrected in the digital domain during reconstruction, achieving superior NSD and distortion performance compared to conventional approaches.Type: ApplicationFiled: October 24, 2022Publication date: March 7, 2024Applicant: Analog Devices International Unlimited CompanyInventors: Sharvil Pradeep PATIL, Asha GANESAN, Hajime SHIBATA, Donald W. PATERSON, Haiyang ZHU
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Patent number: 11652491Abstract: Mechanisms for reducing or eliminating a quantization error caused by a quantizer of a continuous-time (CT) residue generation system are disclosed. In particular, systems and methods described herein are based on using a dither generation and injection circuit that can perform a high-pass filtering of the additive dither signal (i.e., a high-pass shaped dither signal). Using high-pass shaped dither signals is expected to improve quantizer linearity without significantly reducing the available error correction range. The applied dither may be particularly effective at minimizing signal-dependent distortion in ADC output spectrum caused by the quantizer when the quantization error cancellation accuracy may be insufficient.Type: GrantFiled: July 30, 2021Date of Patent: May 16, 2023Assignee: Analog Devices International Unlimited CompanyInventors: Victor Kozlov, Donald W. Paterson, Sharvil Pradeep Patil, Hajime Shibata
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Patent number: 11563442Abstract: Calibration of continuous-time (CT) residue generation systems can account and compensate for mismatches in magnitude and phase that may be caused by fabrication processes, temperature, and voltage variations. In particular, calibration may be performed by providing one or more known test signals as an input to a CT residue generation system, analyzing the output of the system corresponding to the known input, and then adjusting one or more parameters of a forward and/or a feedforward path of the system so that the difference in transfer functions of these paths may be reduced/minimized. Calibrating CT residue generation systems using test signals may help decrease the magnitude of the residue signals generated by such systems, and, consequently, advantageously increase an error correction range of such systems or of further stages that may use the residue signals as input.Type: GrantFiled: July 30, 2021Date of Patent: January 24, 2023Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Victor Kozlov, Sharvil Pradeep Patil, Hajime Shibata
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Publication number: 20220347175Abstract: Provided are: a pyridazinone derivative and/or a pharmaceutically acceptable salt thereof, which is useful as a therapeutic agent and/or a prophylactic agent for diseases in which Nav1.1 is involved and various central nervous system diseases; and a medicine containing the pyridazinone derivative and/or the pharmaceutically acceptable salt thereof as an active ingredient. A compound represented by formula (1) or a pharmaceutically acceptable salt thereof. [In the formula, M1 represents a saturated or partially unsaturated C4-12 carbocyclic group or the like; R1 and R2 independently represent a hydrogen atom or the like; M2 represents a group represented by formula (2a) or the like; X1a, X1b and X1c independently represent N or the like; X2, X3 and X4 independently represent CR3 or the like; A1 and A2 independently represent N or the like; and R3 represents a hydrogen atom or the like.Type: ApplicationFiled: July 18, 2019Publication date: November 3, 2022Applicant: Sumitomo Dainippon Pharma Co., Ltd.Inventors: Tomoaki NISHIDA, Hiro UEMACHI, Masato IWATA, Hajime SHIBATA, Takuya NISHIMAKI, Saori KIYOSHIGE
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Patent number: 11329660Abstract: VCO ADCs consume relatively little power and require less area than other ADC architectures. However, when a VCO ADC is implemented by itself, the VCO ADC can have limited bandwidth and performance. To address these issues, the VCO ADC is implemented as a back end stage in a VCO-based continuous-time (CT) pipelined ADC, where the VCO-based CT pipelined ADC has a CT residue generation front end. Optionally, the VCO ADC back end has phase interpolation to improve its bandwidth. The pipelined architecture dramatically improves the performance of the VCO ADC back end, and the overall VCO-based CT pipelined ADC is simpler than a traditional continuous-time pipelined ADC.Type: GrantFiled: February 15, 2021Date of Patent: May 10, 2022Assignee: Analog Devices International Unlimited CompanyInventors: Hajime Shibata, Gerard E. Taylor, Wenhua W. Yang
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Publication number: 20220102565Abstract: The purpose of the present invention is to improve the reliability of a photovoltaic cell. In the present invention, a photovoltaic cell (CL) comprises a back electrode (BE), a p-type semiconductor layer (semiconductor substrate 1S) disposed on the back electrode (BE), and an n-type semiconductor layer (NL) disposed on the semiconductor substrate (1S). The photovoltaic cell (CL) furthermore comprises: an anti-reflection film (ARF) disposed on the n-type semiconductor layer (NL), the anti-reflection film (ARF) being made of an insulating film; surface electrodes (SE) penetrating the anti-reflection film (ARF) to reach the n-type semiconductor layer (NL); and an electroconductive film (CF) disposed on the anti-reflection film (ARF) so as to cover the surface electrodes (SE), the electroconductive film (CF) being transparent and being electrically connected to the n-type semiconductor layer (NL).Type: ApplicationFiled: August 26, 2019Publication date: March 31, 2022Inventors: Sachiko JONAI, Atsushi MASUDA, Takashi KOIDA, Hajime SHIBATA
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Publication number: 20220045686Abstract: Mechanisms for reducing or eliminating a quantization error caused by a quantizer of a continuous-time (CT) residue generation system are disclosed. In particular, systems and methods described herein are based on using a dither generation and injection circuit that can perform a high-pass filtering of the additive dither signal (i.e., a high-pass shaped dither signal). Using high-pass shaped dither signals is expected to improve quantizer linearity without significantly reducing the available error correction range. The applied dither may be particularly effective at minimizing signal-dependent distortion in ADC output spectrum caused by the quantizer when the quantization error cancellation accuracy may be insufficient.Type: ApplicationFiled: July 30, 2021Publication date: February 10, 2022Applicant: Analog Devices International Unlimited CompanyInventors: Victor KOZLOV, Donald W. PATERSON, Sharvil Pradeep PATIL, Hajime SHIBATA
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Publication number: 20220045687Abstract: Calibration of continuous-time (CT) residue generation systems can account and compensate for mismatches in magnitude and phase that may be caused by fabrication processes, temperature, and voltage variations. In particular, calibration may be performed by providing one or more known test signals as an input to a CT residue generation system, analyzing the output of the system corresponding to the known input, and then adjusting one or more parameters of a forward and/or a feedforward path of the system so that the difference in transfer functions of these paths may be reduced/minimized. Calibrating CT residue generation systems using test signals may help decrease the magnitude of the residue signals generated by such systems, and, consequently, advantageously increase an error correction range of such systems or of further stages that may use the residue signals as input.Type: ApplicationFiled: July 30, 2021Publication date: February 10, 2022Applicant: Analog Devices International Unlimited CompanyInventors: Victor KOZLOV, Sharvil Pradeep PATIL, Hajime SHIBATA
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Patent number: 11218158Abstract: In one aspect, a transfer function (TF) estimation circuit configured to generate an estimate of a TF undergone by signals between an input of a digital-to-analog converter (DAC) of a feedforward path of a continuous-time (CT) stage of an analog-to-digital converter (ADC) and an output of a backend ADC of the ADC is disclosed. The TF estimation circuit includes one or more circuits configured to generate a first cross-correlation output by cross-correlating digital versions of signals based on a test signal provided to the CT stage and an output signal of the backend ADC, generate a second cross-correlation output by cross-correlating digital versions of signals based on the test signal and an output signal of a quantizer of the feedforward path of the CT stage, and generate the estimate of the TF based on the first and second cross-correlation outputs.Type: GrantFiled: January 21, 2021Date of Patent: January 4, 2022Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Sharvil Pradeep Patil, Donald W. Paterson, Prawal Man Shrestha, Asha Ganesan, Yue Yin, Zhao Li, Victor Kozlov, Hajime Shibata
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Patent number: 11133814Abstract: An example residue generation arrangement for a continuous time or hybrid ADC includes a delay circuit having a cascade of analog delay sections, each section to provide a respective delay to an analog input signal, thus providing a delayed analog input signal at the output of the delay circuit. The delay circuit further includes a selector, configured to select an input or an output of one of the delay sections to provide as an input signal to a quantizer of a feedforward path. The quantizer may generate a digital input to a DAC of the feedforward path based on the output of the selector, and the DAC may generate a feedforward path analog output based on the digital signal generated by the quantizer. The arrangement further includes a summation node, configured to generate a residue signal based on the delayed analog input and the feedforward path analog output.Type: GrantFiled: December 3, 2020Date of Patent: September 28, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Sharvil Pradeep Patil, Kimo Tam, Hajime Shibata
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Patent number: 11128310Abstract: Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches and/or errors. The mismatches and/or errors can degrade the quality of the analog output. To extract the mismatches and/or errors, a transparent dither can be used. The mismatches and/or errors can be extracted by observing the analog output, and performing a cross-correlation of the observed output with a switching bit stream of the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the respective mismatches and/or errors.Type: GrantFiled: May 31, 2020Date of Patent: September 21, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Jialin Zhao, Hajime Shibata, Gil Engel, Yunzhi Dong
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Patent number: 11075643Abstract: Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.Type: GrantFiled: February 5, 2020Date of Patent: July 27, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Jialin Zhao, Hajime Shibata, Hao Luo
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Patent number: 11063794Abstract: A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively “holds” or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.Type: GrantFiled: March 27, 2020Date of Patent: July 13, 2021Assignee: Analog Devices International Unlimited CompanyInventors: Hajime Shibata, Brian Holford, Trevor Clifford Caldwell, Siddharth Devarajan
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Publication number: 20210194492Abstract: Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.Type: ApplicationFiled: February 5, 2020Publication date: June 24, 2021Applicant: Analog Devices International Unlimited CompanyInventors: Jialin ZHAO, Hajime SHIBATA, Hao LUO
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Publication number: 20210167790Abstract: VCO ADCs consume relatively little power and require less area than other ADC architectures. However, when a VCO ADC is implemented by itself, the VCO ADC can have limited bandwidth and performance. To address these issues, the VCO ADC is implemented as a back end stage in a VCO-based continuous-time (CT) pipelined ADC, where the VCO-based CT pipelined ADC has a CT residue generation front end. Optionally, the VCO ADC back end has phase interpolation to improve its bandwidth. The pipelined architecture dramatically improves the performance of the VCO ADC back end, and the overall VCO-based CT pipelined ADC is simpler than a traditional continuous-time pipelined ADC.Type: ApplicationFiled: February 15, 2021Publication date: June 3, 2021Applicant: Analog Devices International Unlimited CompanyInventors: Hajime SHIBATA, Gerard E. TAYLOR, Wenhua W. YANG
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Publication number: 20210119636Abstract: Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.Type: ApplicationFiled: December 10, 2019Publication date: April 22, 2021Applicant: Analog Devices International Unlimited CompanyInventors: Jialin ZHAO, Hajime SHIBATA, Gil ENGEL
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Publication number: 20210111732Abstract: Embodiments may relate to a circuit for use in an analog-to-digital converter (ADC) circuit. The circuit may include a first residue amplifier stage and a second residue amplifier stage. The circuit may further include a synthesized delay stage with a digital-to-analog converter (DAC) electrically positioned between a signal input and the input of the second residue amplifier stage. The circuit may further include a resistor electrically positioned between the signal input and the input of the second residue amplifier stage. Other embodiments may be described or claimed.Type: ApplicationFiled: October 15, 2019Publication date: April 15, 2021Applicant: Analog Devices International Unlimited CompanyInventors: Shanthi Pavan YENDLURI, Hajime SHIBATA
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Patent number: 10965302Abstract: Digital to analog conversion generates an analog output corresponding to a digital input by controlling unit elements or cells using data bits of the digital input. The unit elements or cells individually make a contribution to the analog output. Due to process, voltage, and temperature variations, the unit elements or cells may have mismatches. The mismatches can degrade the quality of the analog output. To extract the mismatches, a transparent dither can be used. The mismatches can be extracted by observing the analog output, and performing a cross-correlation of the observed output with the dither. Once extracted, the unit elements or cells can be adjusted accordingly to reduce the mismatches.Type: GrantFiled: December 10, 2019Date of Patent: March 30, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Jialin Zhao, Hajime Shibata, Gil Engel
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Patent number: 10958281Abstract: Embodiments may relate to a circuit for use in an analog-to-digital converter (ADC) circuit. The circuit may include a first residue amplifier stage and a second residue amplifier stage. The circuit may further include a synthesized delay stage with a digital-to-analog converter (DAC) electrically positioned between a signal input and the input of the second residue amplifier stage. The circuit may further include a resistor electrically positioned between the signal input and the input of the second residue amplifier stage. Other embodiments may be described or claimed.Type: GrantFiled: October 15, 2019Date of Patent: March 23, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Shanthi Pavan Yendluri, Hajime Shibata
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Patent number: 10924128Abstract: VCO ADCs consume relatively little power and require less area than other ADC architectures. However, when a VCO ADC is implemented by itself, the VCO ADC can have limited bandwidth and performance. To address these issues, the VCO ADC is implemented as a back end stage in a VCO-based continuous-time (CT) pipelined ADC, where the VCO-based CT pipelined ADC has a CT residue generation front end. Optionally, the VCO ADC back end has phase interpolation to improve its bandwidth. The pipelined architecture dramatically improves the performance of the VCO ADC back end, and the overall VCO-based CT pipelined ADC is simpler than a traditional continuous-time pipelined ADC.Type: GrantFiled: May 24, 2019Date of Patent: February 16, 2021Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANYInventors: Hajime Shibata, Gerard E. Taylor, Wenhua W. Yang