US 12,425,026 B2
High performance inductive sensing all digital phase locked loop
Paul M. Walsh, Cork (IE); Kofi Makinwa, San Jose, CA (US); Matheus Pimenta, Cork (IE); Çagri Gürleyük, Delfgauw (NL); Dermot MacSweeney, Lynnwood, CA (US); Daniel O'Keeffe, Whitechurch (IE); and Dennis R. Seguine, Kalispell, CA (US)
Assigned to Cypress Semiconductor Corporation, San Jose, CA (US)
Filed by Cypress Semiconductor Corporation, San Jose, CA (US)
Filed on Mar. 18, 2024, as Appl. No. 18/608,691.
Application 18/086,193 is a division of application No. 16/721,222, filed on Dec. 19, 2019, granted, now 11,552,635, issued on Jan. 10, 2023.
Application 18/608,691 is a continuation of application No. 18/086,193, filed on Dec. 21, 2022, granted, now 11,973,498.
Claims priority of provisional application 62/850,101, filed on May 20, 2019.
Prior Publication US 2024/0283451 A1, Aug. 22, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H03K 17/95 (2006.01); G01D 5/20 (2006.01); G01R 27/26 (2006.01); G01V 3/10 (2006.01)
CPC H03K 17/9547 (2013.01) [G01D 5/2006 (2013.01); G01R 27/2611 (2013.01); G01V 3/102 (2013.01); H03K 17/9502 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An apparatus comprising:
an inductance-sensing circuit coupled to a sensor, wherein the inductance-sensing circuit comprises:
a digital phase-frequency detector (PFD) to receive a first signal representing a reference frequency and a second signal representing a second signal representing a sensor frequency;
a first capacitive element;
a second capacitive element, wherein:
the first capacitive element is selectively coupled between the sensor and the digital PFD to make a first adjustment of the sensor frequency
the second capacitive element is selectively coupled between the sensor and the digital PFD to make a second adjustment of the sensor frequency, and
an output of the inductance-sensing circuit represents an inductance change of the sensor;
a proportional integral (PI) controller coupled to the digital PFD, the PI controller to selectively couple the first capacitive element and the digital PFD to make the first adjustment; and
a digital filter coupled to the PI controller, the digital filter to provide the output representing the inductance change.