Patents by Inventor Narasimhan Rajagopal
Narasimhan Rajagopal 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: 20250105854Abstract: In described examples, a circuit includes a multiplexer. The multiplexer receives an input voltage and a calibration signal. An analog-to-digital converter (ADC) is coupled to the multiplexer and generates an output code in response to the calibration signal. A storage circuit is coupled to the ADC and stores the input code representative of the calibration signal at an address corresponding to the output code. The stored input code includes an index value and a coarse value.Type: ApplicationFiled: December 9, 2024Publication date: March 27, 2025Inventors: Visvesvaraya Appala Pentakota, Srinivas Kumar Reddy Naru, Chirag Shetty, Eeshan Miglani, Neeraj Shrivastava, Narasimhan Rajagopal, Shagun Dusad
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Patent number: 12206427Abstract: In described examples, a circuit includes a multiplexer. The multiplexer receives an input voltage and a calibration signal. An analog-to-digital converter (ADC) is coupled to the multiplexer and generates an output code in response to the calibration signal. A storage circuit is coupled to the ADC and stores the input code representative of the calibration signal at an address corresponding to the output code. The stored input code includes an index value and a coarse value.Type: GrantFiled: January 31, 2022Date of Patent: January 21, 2025Assignee: Texas Instruments IncorporatedInventors: Visvesvaraya Appala Pentakota, Srinivas Kumar Reddy Naru, Chirag Shetty, Eeshan Miglani, Neeraj Shrivastava, Narasimhan Rajagopal, Shagun Dusad
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Publication number: 20240372557Abstract: A circuit includes a nonlinear analog-to-digital converter (ADC) configured to provide a first digital output based on an analog input signal. The circuit also includes a linearization circuit having a lookup table (LUT) memory configured to store initial calibration data. The linearization circuit is coupled to the nonlinear ADC and is configured to: determine updated calibration data based on the initial calibration data; replace the initial calibration data in the LUT memory with the updated calibration data; and provide a second digital output at a linearization circuit output of the linearization circuit based on the first digital output and the updated calibration data.Type: ApplicationFiled: July 15, 2024Publication date: November 7, 2024Inventors: Narasimhan RAJAGOPAL, Nithin GOPINATH, Viswanathan NAGARAJAN, Neeraj SHRIVASTAVA, Visvesvaraya A. PENTAKOTA, Harshit MOONDRA, Abhinav CHANDRA
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Patent number: 12074607Abstract: A circuit includes a nonlinear analog-to-digital converter (ADC) configured to provide a first digital output based on an analog input signal. The circuit also includes a linearization circuit having a lookup table (LUT) memory configured to store initial calibration data. The linearization circuit is coupled to the nonlinear ADC and is configured to: determine updated calibration data based on the initial calibration data; replace the initial calibration data in the LUT memory with the updated calibration data; and provide a second digital output at a linearization circuit output of the linearization circuit based on the first digital output and the updated calibration data.Type: GrantFiled: May 26, 2022Date of Patent: August 27, 2024Assignee: Texas Instruments IncorporatedInventors: Narasimhan Rajagopal, Nithin Gopinath, Viswanathan Nagarajan, Neeraj Shrivastava, Visvesvaraya A. Pentakota, Harshit Moondra, Abhinav Chandra
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Publication number: 20240187013Abstract: In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.Type: ApplicationFiled: February 13, 2024Publication date: June 6, 2024Inventors: Himanshu Varshney, Viswanathan Nagarajan, Charls Babu, Narasimhan Rajagopal, Eeshan Miglani, Visvesvaraya A. Pentakota
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Patent number: 11962318Abstract: In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.Type: GrantFiled: January 5, 2022Date of Patent: April 16, 2024Assignee: Texas Instruments IncorporatedInventors: Himanshu Varshney, Viswanathan Nagarajan, Charls Babu, Narasimhan Rajagopal, Eeshan Miglani, Visvesvaraya A Pentakota
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Patent number: 11881867Abstract: In described examples, a circuit includes a calibration engine. The calibration engine generates multiple input codes. A digital to analog converter (DAC) is coupled to the calibration engine, and generates a first calibration signal in response to a first input code of the multiple input codes. An analog to digital converter (ADC) is coupled to the DAC, and generates multiple raw codes responsive to the first calibration signal. A storage circuit is coupled to the ADC and stores a first output code corresponding to the first input code. The first output code is obtained using the multiple raw codes generated by the ADC.Type: GrantFiled: September 7, 2021Date of Patent: January 23, 2024Assignee: Texas Instruments IncorporatedInventors: Narasimhan Rajagopal, Eeshan Miglani, Chirag Chandrahas Shetty, Neeraj Shrivastava, Shagun Dusad, Srinivas Kumar Reddy Naru, Nithin Gopinath, Charls Babu, Shivam Srivastava, Viswanathan Nagarajan, Jagannathan Venkataraman, Harshit Moondra, Prasanth K, Visvesvaraya Appala Pentakota
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Publication number: 20230387932Abstract: A circuit includes a nonlinear analog-to-digital converter (ADC) configured to provide a first digital output based on an analog input signal. The circuit also includes a linearization circuit having a lookup table (LUT) memory configured to store initial calibration data. The linearization circuit is coupled to the nonlinear ADC and is configured to: determine updated calibration data based on the initial calibration data; replace the initial calibration data in the LUT memory with the updated calibration data; and provide a second digital output at a linearization circuit output of the linearization circuit based on the first digital output and the updated calibration data.Type: ApplicationFiled: May 26, 2022Publication date: November 30, 2023Inventors: Narasimhan RAJAGOPAL, Nithin GOPINATH, Viswanathan NAGARAJAN, Neeraj SHRIVASTAVA, Visvesvaraya A. PENTAKOTA, Harshit MOONDRA, Abhinav CHANDRA
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Patent number: 11641216Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.Type: GrantFiled: March 8, 2022Date of Patent: May 2, 2023Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Sarma Sundareswara Gunturi, Jagannathan Venkataraman, Jawaharlal Tangudu, Narasimhan Rajagopal, Eeshan Miglani
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Patent number: 11438001Abstract: A method of using an analog-to-digital converter system includes receiving a sampled voltage corresponding to one of an input voltage and a known voltage, causing preamplifiers to generate output signals based on the sampled voltage, generating first and second signals based on the output signals, causing a delay-resolving delay-to-digital backend to generate a single-bit digital signal representing an order of receipt of the first and second signals, and adjusting one or more of the preamplifiers based on the digital signal. The disclosure also relates to a system which includes a voltage-to-delay frontend and a delay-resolving backend, and to a method which includes causing a delay comparator to generate a single-bit digital signal representing an order of receipt of input signals, causing the comparator to transmit a residue delay signal to a succeeding comparator, and transmitting a signal to adjust one or more of the preamplifiers based on the digital signal.Type: GrantFiled: December 24, 2020Date of Patent: September 6, 2022Assignee: Texas Instruments IncorporatedInventors: Narasimhan Rajagopal, Chirag Chandrahas Shetty, Neeraj Shrivastava, Prasanth K, Eeshan Miglani
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Publication number: 20220247421Abstract: In described examples, a circuit includes a multiplexer. The multiplexer receives an input voltage and a calibration signal. An analog-to-digital converter (ADC) is coupled to the multiplexer and generates an output code in response to the calibration signal. A storage circuit is coupled to the ADC and stores the input code representative of the calibration signal at an address corresponding to the output code. The stored input code includes an index value and a coarse value.Type: ApplicationFiled: January 31, 2022Publication date: August 4, 2022Inventors: Visvesvaraya Appala Pentakota, Srinivas Kumar Reddy Naru, Chirag Shetty, Eeshan Miglani, Neeraj Shrivastava, Narasimhan Rajagopal, Shagun Dusad
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Publication number: 20220247420Abstract: In described examples, a circuit includes a calibration engine. The calibration engine generates multiple input codes. A digital to analog converter (DAC) is coupled to the calibration engine, and generates a first calibration signal in response to a first input code of the multiple input codes. An analog to digital converter (ADC) is coupled to the DAC, and generates multiple raw codes responsive to the first calibration signal. A storage circuit is coupled to the ADC and stores a first output code corresponding to the first input code. The first output code is obtained using the multiple raw codes generated by the ADC.Type: ApplicationFiled: September 7, 2021Publication date: August 4, 2022Inventors: Narasimhan Rajagopal, Eeshan Miglani, Chirag Chandrahas Shetty, Neeraj Shrivastava, Shagun Dusad, Srinivas Kumar Reddy Naru, Nithin Gopinath, Charls Babu, Shivam Srivastava, Viswanathan Nagarajan, Jagannathan Venkataraman, Harshit Moondra, Prasanth K, Visvesvaraya Appala Pentakota
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Publication number: 20220224349Abstract: In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.Type: ApplicationFiled: January 5, 2022Publication date: July 14, 2022Inventors: Himanshu Varshney, Viswanathan Nagarajan, Charls Babu, Narasimhan Rajagopal, Eeshan Miglani, Visvesvaraya A. Pentakota
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Publication number: 20220209782Abstract: A method of using an analog-to-digital converter system includes receiving a sampled voltage corresponding to one of an input voltage and a known voltage, causing preamplifiers to generate output signals based on the sampled voltage, generating first and second signals based on the output signals, causing a delay-resolving delay-to-digital backend to generate a single-bit digital signal representing an order of receipt of the first and second signals, and adjusting one or more of the preamplifiers based on the digital signal. The disclosure also relates to a system which includes a voltage-to-delay frontend and a delay-resolving backend, and to a method which includes causing a delay comparator to generate a single-bit digital signal representing an order of receipt of input signals, causing the comparator to transmit a residue delay signal to a succeeding comparator, and transmitting a signal to adjust one or more of the preamplifiers based on the digital signal.Type: ApplicationFiled: December 24, 2020Publication date: June 30, 2022Inventors: Narasimhan RAJAGOPAL, Chirag Chandrahas SHETTY, Neeraj SHRIVASTAVA, Prasanth K, Eeshan MIGLANI
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Publication number: 20220190856Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.Type: ApplicationFiled: March 8, 2022Publication date: June 16, 2022Inventors: Sarma Sundareswara GUNTURI, Jagannathan VENKATARAMAN, Jawaharlal TANGUDU, Narasimhan RAJAGOPAL, Eeshan MIGLANI
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Patent number: 11316525Abstract: An analog-to-digital converter system includes a digital-to-analog converter for generating calibration voltages based on digital input codes, and an analog-to-digital converter, connected to the digital-to-analog converter, for receiving the calibration voltages from the digital-to-analog converter, for receiving sampled voltages, for generating digital output codes based on the calibration voltages, and for generating digital output codes based on the sampled voltages. The analog-to-digital converter system may have a lookup table, connected to the analog-to-digital converter, for storing the first digital output codes in association with the digital input codes. A method of calibrating an analog-to-digital converter system is also disclosed.Type: GrantFiled: January 26, 2021Date of Patent: April 26, 2022Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Visvesvaraya Appala Pentakota, Narasimhan Rajagopal, Chirag Chandrahas Shetty, Prasanth K, Neeraj Shrivastava, Eeshan Miglani, Jagannathan Venkataraman
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Patent number: 11316526Abstract: An analog-to-digital converter includes a voltage-to-delay device, such as a pre-amplifier array, for generating a delay signal based on a first voltage, and delay-based stages for generating digital signals based on the delay signal. In operation, the delay signal is transmitted to a first delay-based stage, or to an intermediate delay-based stage, bypassing the first delay-based stage, to overcome non-linearity of previous stages. If desired, different pre-amplifiers may be used to generate signals for calibration of different delay-based stages. The present disclosure may also involve converting to pseudo-static signals before signals are handed over to a calibration engine, to ease timing and preserve interface area and power. If desired, simple delay elements may be used to correct for non-linearity in a delay-based analog-to-digital converter. The present disclosure may be employed, if desired, in connection with any suitable cascade of non-linear stages.Type: GrantFiled: December 18, 2020Date of Patent: April 26, 2022Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Narasimhan Rajagopal, Visvesvaraya Appala Pentakota, Eeshan Miglani
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Patent number: 11309902Abstract: In described examples, a stochastic comparator includes a first comparator that compares an input signal and a primary threshold to generate a first signal. A second comparator compares the input signal and the primary threshold to generate a second signal. A decision block generates a control signal in response to the first signal, the second signal and a PRBS (pseudo random binary sequence) signal. A XOR gate generates a detection signal in response the first signal and the second signal.Type: GrantFiled: December 16, 2019Date of Patent: April 19, 2022Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Srinivas Kumar Reddy Naru, Narasimhan Rajagopal, Shagun Dusad, Viswanathan Nagarajan, Visvesvaraya Appala Pentakota
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Patent number: 11303312Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.Type: GrantFiled: December 4, 2020Date of Patent: April 12, 2022Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Sarma Sundareswara Gunturi, Jagannathan Venkataraman, Jawaharlal Tangudu, Narasimhan Rajagopal, Eeshan Miglani
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Publication number: 20210175914Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.Type: ApplicationFiled: December 4, 2020Publication date: June 10, 2021Inventors: Sarma Sundareswara GUNTURI, Jagannathan VENKATARAMAN, Jawaharlal TANGUDU, Narasimhan RAJAGOPAL, Eeshan MIGLANI