公开(公告)号：US20160109327A1

公开(公告)日：2016-04-21

申请号：US14515724

申请日：2014-10-16

Applicant: Texas Instruments Incorporated

Inventor： Nagarajan Viswanathan

IPC: G01M11/00

CPC classification number: G01M11/3145

Abstract: Optical time domain reflectometer (OTDR) systems, methods and integrated circuits are presented for locating defects in an optical cable or other optical cable, in which a first optical signal is transmitted to the cable and reflections are sampled over a first time range at a first sample rate to identify one or more suspected defect locations, and a second optical signal is transmitted and corresponding reflections are sampled over a second smaller time range at a higher second sample rate to identify at least one defect location of the optical cable for relaxed memory requirements in the OTDR system.

Abstract translation: 提出了光时域反射计（OTDR）系统，方法和集成电路，用于定位光缆或其他光缆中的缺陷，其中第一光信号被传输到电缆，并且反射在第一时间范围内被采样 采样率以识别一个或多个可疑缺陷位置，并且发送第二光信号，并且以较高的第二采样率在第二较小时间范围上对相应的反射进行采样，以识别用于放宽存储器要求的光缆的至少一个缺陷位置 在OTDR系统中。

公开(公告)号：US11777513B2

公开(公告)日：2023-10-03

申请号：US17538746

申请日：2021-11-30

Applicant: Texas Instruments Incorporated

Inventor： Karthikeyan Gunasekaran ,  Snehasish Roychowdhury ,  Rakesh Manjunath ,  Aswath V S ,  Sthanunathan Ramakrishnan ,  Sarma Sudareswara Gunturi ,  Rahul Sharma ,  Jagannathan Venkataraman ,  Nagarajan Viswanathan

IPC: H03M1/10 ,  H03M1/66 ,  H03M1/06 ,  H03M1/08

CPC classification number: H03M1/1033 ,  H03M1/0631 ,  H03M1/0863 ,  H03M1/662

Abstract: A spur correction system for a transmit chain having an interleaving multiplexer. In some embodiments, the spur correction system includes a spur sense chain, a correction controller, and a Q path corrector. The interleaving multiplexer combines signals from multiple bands in response to a clock signal. The spur sense chain estimates an error that is in phase with the clock signal (an I-phase error) and an error that is a derivative of the clock signal (a Q-phase error). The correction controller compensates for the estimated I-phase error by injecting an I-phase correction signal into the transmit chain. The Q path corrector compensates for the estimated Q-phase error by selectively connecting one or more capacitors within the interleaving multiplexer.

公开(公告)号：US09341543B2

公开(公告)日：2016-05-17

申请号：US14515724

申请日：2014-10-16

Applicant: Texas Instruments Incorporated

Inventor： Nagarajan Viswanathan

IPC: G01M11/00

CPC classification number: G01M11/3145

Abstract: Optical time domain reflectometer (OTDR) systems, methods and integrated circuits are presented for locating defects in an optical cable or other optical cable, in which a first optical signal is transmitted to the cable and reflections are sampled over a first time range at a first sample rate to identify one or more suspected defect locations, and a second optical signal is transmitted and corresponding reflections are sampled over a second smaller time range at a higher second sample rate to identify at least one defect location of the optical cable for relaxed memory requirements in the OTDR system.

Abstract translation: 提出了光时域反射计（OTDR）系统，方法和集成电路，用于定位光缆或其他光缆中的缺陷，其中第一光信号被传输到电缆，并且反射在第一时间范围内被采样 采样率以识别一个或多个可疑缺陷位置，并且发送第二光信号，并且以较高的第二采样率在第二较小时间范围上对相应的反射进行采样，以识别用于放宽存储器要求的光缆的至少一个缺陷位置 在OTDR系统中。

公开(公告)号：US09184762B2

公开(公告)日：2015-11-10

申请号：US14656205

申请日：2015-03-12

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sthanunathan Ramakrishnan ,  Sashidharan Venkatraman ,  Sreenath Narayanan Potty ,  Sunil Chomal ,  Nagarajan Viswanathan ,  Jawaharlal Tangudu

IPC: H03M1/10 ,  H03M1/36 ,  H03M1/08 ,  H03M1/06 ,  H03M1/12

CPC classification number: H03M1/368 ,  H03M1/06 ,  H03M1/0836 ,  H03M1/1038 ,  H03M1/1085 ,  H03M1/121 ,  H03M1/1215

Abstract: A system can include a signal image correlator receives a discrete frequency domain representation of a signal tone in an interleaved analog-to-digital (IADC) signal and an image of the signal tone in the discrete frequency domain representation of the IADC signal and determines a correlation between the signal tone and the image of the signal tone, a power of the signal tone and a power of the image of the signal tone. The system can also include a frequency domain estimator that determines an instantaneous frequency domain mismatch profile estimate based on the correlation between the signal tone and the image of the signal tone. The system can further include an averaging filter that averages the instantaneous frequency domain mismatch profile estimate over time to provide a frequency domain mismatch profile estimate.

Abstract translation: 系统可以包括信号图像相关器接收交织的模数（IADC）信号中的信号音的离散频域表示和IADC信号的离散频域表示中的信号音的图像，并且确定 信号音和信号音的图像之间的相关性，信号音的功率和信号音的图像的功率。 该系统还可以包括频域估计器，其基于信号音和信号音的图像之间的相关性来确定瞬时频域失配曲线估计。 该系统还可以包括平均滤波器，其对瞬时频域失配曲线估计进行平均以提供频域不匹配曲线估计。

公开(公告)号：US20150263753A1

公开(公告)日：2015-09-17

申请号：US14656205

申请日：2015-03-12

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： STHANUNATHAN RAMAKRISHNAN ,  Sashidharan Venkatraman ,  Sreenath Narayanan Potty ,  Sunil Chomal ,  Nagarajan Viswanathan ,  Jawaharlal Tangudu

IPC: H03M1/36 ,  H03M1/08

CPC classification number: H03M1/368 ,  H03M1/06 ,  H03M1/0836 ,  H03M1/1038 ,  H03M1/1085 ,  H03M1/121 ,  H03M1/1215

Abstract: A system can include a signal image correlator receives a discrete frequency domain representation of a signal tone in an interleaved analog-to-digital (IADC) signal and an image of the signal tone in the discrete frequency domain representation of the IADC signal and determines a correlation between the signal tone and the image of the signal tone, a power of the signal tone and a power of the image of the signal tone. The system can also include a frequency domain estimator that determines an instantaneous frequency domain mismatch profile estimate based on the correlation between the signal tone and the image of the signal tone. The system can further include an averaging filter that averages the instantaneous frequency domain mismatch profile estimate over time to provide a frequency domain mismatch profile estimate.

Abstract translation: 系统可以包括信号图像相关器接收交织的模数（IADC）信号中的信号音的离散频域表示和IADC信号的离散频域表示中的信号音的图像，并且确定 信号音和信号音的图像之间的相关性，信号音的功率和信号音的图像的功率。 该系统还可以包括频域估计器，其基于信号音和信号音的图像之间的相关性来确定瞬时频域失配曲线估计。 该系统还可以包括平均滤波器，其对瞬时频域失配曲线估计进行平均以提供频域不匹配曲线估计。

公开(公告)号：US20150188626A1

公开(公告)日：2015-07-02

申请号：US14579380

申请日：2014-12-22

Applicant: Texas Instruments Incorporated

Inventor： Nagarajan Viswanathan

IPC: H04B10/071 ,  G01M11/00

CPC classification number: H04B10/071 ,  G01M11/3109 ,  G01M11/3118 ,  G01M11/3127

Abstract: An optical data transmitter is operable to transmit data other than test data on an optical fiber at a first wavelength and an optical time domain reflectometer is operable to receive data from the optical fiber at the first wavelength and to use the received data at the first wavelength to determine whether a defect exists in the optical fiber.

Abstract translation: 光学数据发射器可操作以在第一波长的光纤上发送除测试数据之外的数据，并且光学时域反射计可操作以从第一波长的光纤接收数据，并使用第一波长的接收数据 以确定光纤中是否存在缺陷。

公开(公告)号：US09001712B2

公开(公告)日：2015-04-07

申请号：US13872093

申请日：2013-04-27

Applicant: Texas Instruments Incorporated

Inventor： Nagarajan Viswanathan ,  Visvesvaraya Pentakota ,  Robert Clair Keller ,  Thomas Neu ,  Francesco Dantoni

IPC: H04B1/52 ,  H04L5/14

CPC classification number: H04L5/1461 ,  H04B1/525

Abstract: Apparatus and methods disclosed herein implement an RF receive-band filter at a receive chain input of a wireless base station with a co-located transmitter and receiver. The RF receive-band filter includes an adaptive filter component to perform filtering operations on samples of a digital baseband or intermediate frequency signal x(n) from a transmit chain associated with the wireless base station. An adaptive filter transfer function is determined in real time such that samples of the baseband transmit signal x(n) are transformed into a cancellation baseband signal z(n). The digital cancelation baseband signal z(n) is then digital-to-analog converted and the resulting analog baseband signal z(t) is up-converted to obtain a subtractive RF cancelation signal c(t). C(t) is summed with a desirable received signal RF component r(t) and an undesirable transmitter leakage RF signal component l(t) appearing at the input to the base station receiver. C(t) cancels l(t), leaving r(t) to be processed by the receiver section of the base station.

Abstract translation: 本文公开的装置和方法在具有共位发射器和接收器的无线基站的接收链输入端实现RF接收带滤波器。 RF接收带滤波器包括自适应滤波器组件，用于对与无线基站相关联的发射链进行数字基带或中频信号x（n）的采样执行滤波操作。 实时地确定自适应滤波器传递函数，使得基带发送信号x（n）的采样被变换为消除基带信号z（n）。 然后对数字消除基带信号z（n）进行数模转换，并将所得到的模拟基带信号z（t）上变频以获得减法RF消除信号c（t）。 C（t）与期望的接收信号RF分量r（t）和出现在基站接收机的输入处的不期望的发射机泄漏RF信号分量l（t）相加。 C（t）取消l（t），使r（t）由基站的接收机部分处理。

公开(公告)号：US12166500B2

公开(公告)日：2024-12-10

申请号：US18461152

申请日：2023-09-05

Applicant: Texas Instruments Incorporated

Inventor： Nagarajan Viswanathan ,  Himanshu Varshney ,  Vinam Arora ,  Charls Babu ,  Srinivas Kumar Naru

IPC: H03M1/10 ,  H03M1/36 ,  H03M1/50

Abstract: In an example, a system includes an input channel and a voltage to delay converter (V2D) coupled to the input channel. The system also includes a first multiplexer coupled to the V2D and an analog-to-digital converter (ADC) coupled to the first multiplexer. The system includes a second multiplexer coupled to the input channel and an auxiliary ADC coupled to the second multiplexer. The system includes calibration circuitry coupled to an output of the auxiliary ADC, where the calibration circuitry is configured to correct a non-linearity in a signal provided by the input channel. The calibration circuitry is also configured to determine the non-linearity of the signal provided to the ADC relative to the signal provided to the auxiliary ADC.

公开(公告)号：US10741268B2

公开(公告)日：2020-08-11

申请号：US16235698

申请日：2018-12-28

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Aravind Ganesan ,  Jaiganesh Balakrishnan ,  Nagarajan Viswanathan ,  Yeswanth Guntupalli ,  Ajai Paulose ,  Mathews John ,  Jagannathan Venkataraman ,  Neeraj Shrivastava

IPC: G11C29/02 ,  G11C17/14 ,  G11C17/16 ,  G11C17/18

Abstract: A one-time write, read-only memory for storing trimming parameters includes an address pointer table, a fixed packet portion, and a flexible packet portion. The fixed packet portion includes one or more fixed packets, each fixed packet including trimming parameters for a component identified for trimming during a design phase. The flexible packet portion includes one or more flexible packets of different types. Each flexible packet includes trimming parameters for a component identified for trimming after the design phase. One packet type includes a length section and a number of fields equal to a value stored in the length section. Each field includes an address, a trimming parameter, and a mask. Another packet type includes trimming parameters associated with operands in operating instructions for a microcontroller, where the operands include an address and a mask.

公开(公告)号：US20170324421A1

公开(公告)日：2017-11-09

申请号：US15389236

申请日：2016-12-22

Applicant: Texas Instruments Incorporated

Inventor： Jawaharlal Tangudu ,  Sthanunathan Ramakrishnan ,  Nagarajan Viswanathan ,  Pooja Sundar

IPC: H03M1/06 ,  H03M1/12 ,  H03M1/10

CPC classification number: H03M1/0617 ,  H03M1/1009 ,  H03M1/1042 ,  H03M1/1215 ,  H03M1/1245

Abstract: Methods and apparatus for reducing non-linearity in analog to digital converters are disclosed. An example apparatus includes an analog-to-digital converter to convert an analog signal into a digital signal; and a non-linearity corrector coupled to the analog-to-digital converter to determine a derivative of the digital signal; determine cross terms including a combination of the digital signal and the derivative of the digital signal; and determine a non-linearity term corresponding to a combination of the cross terms.