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:
Oct. 06, 2020
Filed:
Dec. 03, 2018
Cirrus Logic International Semiconductor Ltd., Edinburgh, GB;
Cirrus Logic, Inc., Austin, TX (US);
Abstract
Embodiments described herein relate to methods and apparatus for driving a haptic transducer with a driving signal. The method comprises estimating, based on a current through the haptic transducer and a terminal voltage across the haptic transducer, a back electromotive force, EMF, voltage representative of a velocity of a mass in the haptic transducer; comparing a phase of a voltage signal derived from the terminal voltage with a phase of the estimated back EMF voltage; and based on the comparison, adjusting a frequency or a phase of an output signal, wherein the driving signal is derived from the output signal, such that a frequency of the driving signal converges to a resonant frequency of the haptic transducer.