公开(公告)号：US20200275206A1

公开(公告)日：2020-08-27

申请号：US15930957

申请日：2020-05-13

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： RAHMI HEZAR ,  RAJAN NARASIMHA ,  SRINATH RAMASWAMY

IPC: H04R3/04 ,  H03F3/217 ,  H03F1/32 ,  H03F3/187

Abstract: A system for driving an audio speaker that has an impedance, the system comprising: a scaler having an analog input and a scaler output that is an attenuated analog input; an amplifier having an amplifier input coupled to the scaler output and an amplifier output; a current sensor having a sensor input coupled to the speaker and a sensor output, the current sensor configured to generate a sensor signal at the sensor output responsive to a current from the audio speaker; and a compensator circuit having a circuit input coupled to the sensor output and a circuit output coupled to the amplifier input, the compensator circuit configured to supply a compensation signal to the amplifier input by applying a transfer function to the sensor signal.

公开(公告)号：US20180324524A1

公开(公告)日：2018-11-08

申请号：US15584532

申请日：2017-05-02

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： RAHMI HEZAR ,  RAJAN NARASIMHA ,  SRINATH RAMASWAMY

IPC: H04R3/04 ,  H03F3/217 ,  G01R19/00

Abstract: One example includes a system that is comprised of a speaker, an amplifier, a current sensor, and a compensator circuit. The speaker produces audio in response to an amplified analog input signal received at a speaker input. The amplifier receives an analog audio input signal and provides the amplified analog audio input signal to the speaker input. The current sensor senses current passing through the speaker and provides a current sensor signal indicative thereof. The compensator circuit applies a transfer function to the current sensor signal to provide a compensation signal as feedback into the analog audio input signal, the transfer function matching at least one of resistance and inductance of the speaker.

公开(公告)号：US20180188293A1

公开(公告)日：2018-07-05

申请号：US15395789

申请日：2016-12-30

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： ARUP POLLEY ,  SRINATH RAMASWAMY ,  BAHER S. HAROUN

IPC: G01R15/14 ,  G01R19/00

CPC classification number: G01R15/148 ,  G01R15/185 ,  G01R15/207

Abstract: One example includes a current measurement system. The system includes at least two magnetic field sensors positioned proximal to and in a predetermined arrangement with respect to a current conductor, each of the magnetic field sensors being configured to measure magnetic field associated with a current flowing in the current conductor and provide respective magnetic field measurements. The system also includes a current measurement processor configured to implement a mathematical algorithm based on a Taylor series expansion of the magnetic field measurements to calculate an amplitude of the current based on the mathematical algorithm.

公开(公告)号：US20180180652A1

公开(公告)日：2018-06-28

申请号：US15389053

申请日：2016-12-22

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： CHARLES KASIMER SESTOK, IV ,  SRINATH RAMASWAMY ,  ANAND GANESH DABAK ,  DOMINGO G. GARCIA ,  BAHER HAROUN ,  ALAN HENRY LEEK ,  RYAN MICHAEL BROWN

IPC: G01R27/16

CPC classification number: G01R27/16 ,  G01R27/14

Abstract: A microcontroller-based system for measuring the impedance of a device under test (DUT), responsive to a square wave stimulus, includes parallel stimulus signal paths, selectable by a switch, that can correspond to different stimulus frequency ranges. At least one of the paths includes an off-chip PLL and integer divider circuit to modify the frequency of the stimulus. A discrete Fourier transform executed by a processor is used to determine the impedance of the DUT at the stimulus frequency. Multiple frequencies can be analyzed at the same time by using a summation circuit and/or by analyzing odd harmonics of the stimulus frequency.