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. 26, 2020
Filed:
Oct. 10, 2018
Cirrus Logic International Semiconductor Ltd., Edinburgh, GB;
Lei Zhu, Austin, TX (US);
Jing Bai, Austin, TX (US);
Xiaofan Fei, Austin, TX (US);
Xin Zhao, Austin, TX (US);
CIRRUS LOGIC, INC., Austin, TX (US);
Abstract
An apparatus detects a short of a class-D amplifier. A pulse detector detects an output PWM pulse exceeds a predetermined width and a controller differentiates whether the pulse width exceeding is caused by a short or by a large digital input signal occurring during normal operation based on an expected level of the digital input signal to a level of the digital input signal when the pulse width exceeds the predetermined width. The expected level is dynamically obtained in response to one or more previous PWM pulses exceeding the predetermined width during the normal operation and may be selected based on an amount the pulse exceeds the predetermined width. A lookup table of predetermined levels, selected based on impedance of a load, provides the expected level if the expected level has not yet been dynamically obtained when the pulse width exceeds.