US 12,092,653 B2
Sensing an ICMFB output to detect functional state of a mems sensor
Davy Choi, Carrollton, TX (US); Yamu Hu, Allen, TX (US); and Deyou Fang, Frisco, TX (US)
Assigned to STMicroelectronics, Inc., Coppell, TX (US)
Filed by STMicroelectronics, Inc., Coppell, TX (US)
Filed on Sep. 10, 2021, as Appl. No. 17/472,126.
Application 17/472,126 is a division of application No. 15/599,234, filed on May 18, 2017, granted, now 11,143,670.
Prior Publication US 2021/0405085 A1, Dec. 30, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G01P 21/00 (2006.01); G01P 15/125 (2006.01); G01R 19/10 (2006.01); G01R 31/28 (2006.01)
CPC G01P 21/00 (2013.01) [G01P 15/125 (2013.01); G01R 19/10 (2013.01); G01R 31/2829 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method comprising:
monitoring an input common-mode feedback (ICMFB) voltage generated by an ICMFB circuit, the ICMFB coupled to a microelectromechanical system (MEMS) sensor through a plurality of nodes, the monitoring comprising:
measuring, by a sample and hold (S/H) circuit, a first ICMFB voltage generated by the ICMFB circuit operating in a first operating mode, and
measuring, by the S/H circuit, a second ICMFB voltage generated by the ICMFB circuit in a second operating mode, the second operating mode being a reverse input polarity mode of the first operating mode;
computing a first differential voltage corresponding to a difference between the first ICMFB voltage and the second ICMFB voltage;
reading a predetermined voltage stored in a memory;
computing a second differential voltage corresponding to a difference between the first differential voltage and the predetermined voltage, wherein the predetermined voltage is read from memory before computing the second differential voltage; and
determining whether all of the plurality of nodes are electrically connected to the ICMFB circuit in accordance with the second differential voltage.