公开(公告)号：US11061100B2

公开(公告)日：2021-07-13

申请号：US16576963

申请日：2019-09-20

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Tony Ray Larson ,  Dimitar Trifonov ,  Chao-Hsiuan Tsay ,  Partha Sarathi Basu

IPC: G01R35/00 ,  G01R15/20 ,  G01R33/07 ,  H03M1/12

Abstract: A system comprises a calibration current generator, which provides a calibration current to a first and a second Hall channel, and a bias current generator, which determines a difference between a calibration signal from the Hall channels and a threshold and adjusts a biasing current for the Hall channels based on the difference. In some embodiments, the bias current generator comprises a subtractor coupled to an ADC and a controller coupled between the ADC and a DAC. The subtractor obtains a first and a second signal from the first and second Hall channels, respectively, and subtracts the first from the second to obtain the calibration signal. The controller determines the difference between a sampled signal from the ADC and the threshold and an adjustment to the biasing current based on the difference. The DAC adjusts the biasing current based on a control signal from the controller indicating the adjustment.

公开(公告)号：US20180337639A1

公开(公告)日：2018-11-22

申请号：US15982666

申请日：2018-05-17

Applicant: Texas Instruments Incorporated

Inventor： Tony Ray Larson ,  Dimitar Trifonov Trifonov ,  Biraja Prasad Dash

IPC: H03F1/26 ,  H03F3/387

CPC classification number: H03F1/26 ,  H03F3/387 ,  H03F3/45475 ,  H03F3/45968 ,  H03F2200/171 ,  H03F2200/271 ,  H03F2200/375 ,  H03F2200/459

Abstract: Embodiments relate to a chopped amplifier system where a ripple reduction filter placed outside of a main signal path is disclosed. The chopped amplifier system includes a chopped amplifier having an input terminal and an output terminal, where the input terminal receives an input signal and the output terminal provides an output signal including a ripple that is based on an offset voltage of the chopped amplifier. The ripple reduction filter is placed in a feedback loop path that receives a portion of the chopped amplifier's output signal and provides a feedback signal to the chopped amplifier that reduces the ripple at the output of the chopped amplifier. The ripple reduction filter includes a digital controller and other circuits that can handle large disturbances such as large signal slew rate events and large common-mode steps without reducing the effectiveness of the ripple reduction filter in reducing the ripple.