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.