The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2019
Filed:
Sep. 02, 2016
Texas Instruments Incorporated, Dallas, TX (US);
George Reitsma, Redwood City, CA (US);
TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US);
Abstract
For inductive sensing (such as for proximity switching), differential inductance readout is based on Sense/Reference resonators implemented as LC-ring oscillators, with L/Linductor coils and a shared (time-multiplexed) resonator capacitor. The ring oscillators include matched Lsense/Lref drivers time-multiplexed (by out enable signals), to provide Lsense/Lref resonator excitation signals to the Lsense/Lref resonators, based on resulting Lsense/Lref resonance measurements (such as of resonance state) acquired by the ring oscillators from the Lsense/Lref resonators. Differential readout data is based on the time-multiplexed Lsense/Lref resonance measurements, corresponding respectively to L/Lcoil inductances (such as based on Lsense/Lref resonator oscillation frequency). The ring oscillators can be implemented with a Schmitt trigger, converting analog resonance measurements into digital input to the Lsense/Lref drivers. Driver matching and layout matching can be used to improve accuracy. Effects of parasitic capacitance at the driver outputs can be suppressed by shorting or bootstrapping across the inactive L/Lcoil inductances.