US 12,292,309 B2
Sensitivity equalization in multi-sensor inductive sensing applications
Siddharth Maru, Austin, TX (US); Josh Sanz-Robinson, Austin, TX (US); Tejasvi Das, Austin, TX (US); and John L. Melanson, Austin, TX (US)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Mar. 24, 2021, as Appl. No. 17/211,073.
Prior Publication US 2022/0307872 A1, Sep. 29, 2022
Int. Cl. G01D 18/00 (2006.01); G01D 5/20 (2006.01)
CPC G01D 18/00 (2013.01) [G01D 5/20 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A system comprising:
a plurality of resistive-inductive-capacitive sensors, each resistive-inductive-capacitive sensor configured to sense a physical pressure that modifies a resonant frequency of such resistive-inductive-capacitive sensor; and
a calibration subsystem configured to perform a calibration comprising:
comparing the resonant frequency from each of at least two sensors of the plurality of resistive-inductive-capacitive sensors to determine a sensitivity drift of at least one sensor of the plurality of resistive-inductive-capacitive sensors;
based on the measured characteristics of the at least two sensors and stored reference characteristics for the at least two sensors, calculating a gain correction factor for the at least one sensor;
based on the gain correction factor for the at least one sensor and an estimated quality factor for the at least one sensor, calculating a normalization factor for the at least one sensor; and
applying the normalization factor to the measured characteristic of the at least one sensor to equalize sensitivity of the plurality of resistive-inductive-capacitive sensors relative to each other.