US 12,130,159 B2
Detecting and adapting to changes in a resonant phase sensing system having a resistive-inductive-capacitive sensor
Siddharth Maru, Austin, TX (US); Tejasvi Das, Austin, TX (US); Zhong You, Austin, TX (US); Johann G. Gaboriau, Austin, TX (US); Matthew Beardsworth, Austin, TX (US); and Gregory C. Yancey, Austin, TX (US)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Aug. 6, 2019, as Appl. No. 16/532,850.
Claims priority of provisional application 62/721,134, filed on Aug. 22, 2018.
Claims priority of provisional application 62/739,970, filed on Oct. 2, 2018.
Claims priority of provisional application 62/740,129, filed on Oct. 2, 2018.
Prior Publication US 2020/0064160 A1, Feb. 27, 2020
Int. Cl. G01D 5/243 (2006.01); G01D 5/14 (2006.01); G01D 5/16 (2006.01); G01D 5/20 (2006.01); G01D 5/24 (2006.01); G06F 3/01 (2006.01); H03K 17/95 (2006.01)
CPC G01D 5/243 (2013.01) [G01D 5/14 (2013.01); G01D 5/16 (2013.01); G01D 5/20 (2013.01); G01D 5/24 (2013.01); G06F 3/01 (2013.01); H03K 17/9522 (2013.01); H03K 17/9537 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A system comprising:
a resistive-inductive-capacitive sensor;
a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to:
generate a voltage oscillation signal;
phase shift the voltage oscillation signal; convert the phase shifted voltage oscillation signal to a current signal;
drive the resistive-inductive-capacitive sensor with the current signal;
measure phase information associated with the resistive-inductive-capacitive sensor being driven by the current signal; and
based on the phase information, determine a displacement of a mechanical member relative to the resistive-inductive-capacitive sensor, wherein the mechanical member is disposed within a planar region, and wherein the displacement is a displacement along an axis perpendicular to the planar region; and
a filter communicatively coupled to the measurement circuit, wherein a filter time constant of the filter is larger than a predetermined reference time, such that the filter is configured to isolate changes to the displacement which are slower than the predetermined reference time, and wherein the filter time constant is programmable based on an external stimulus such that different filter time constants are associated with different functionalities for the mechanical member, wherein a first filter time constant is associated with actuating a virtual power button, and wherein a second filter time constant is associated with actuating a different virtual button.