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:
Sep. 19, 2023
Filed:
Nov. 07, 2022
Apple Inc., Cupertino, CA (US);
Yikun Chang, Fremont, CA (US);
Charles L Wang, Los Altos, CA (US);
Chih-Yuan Chen, Santa Clara, CA (US);
APPLE INC., Cupertino, CA (US);
Abstract
An Integrated Circuit includes a target circuit, first and second logic chains, a feedback path and calibration circuitry. The target circuit includes first and second inputs. The first and second logic chains propagate a signal from a common input point to the first and second inputs of the target circuit, respectively. The feedback path receives the signal from the first or second input and feeds the signal back to the common input point. The calibration circuitry is configured to connect the first input to the feedback path thereby forming a first closed-loop oscillator circuit, and measure a first oscillation frequency of the first closed-loop oscillator circuit, connect the second input to the feedback path, thereby forming a second closed-loop oscillator circuit, and measure a second oscillation frequency of the second closed-loop oscillator circuit, and verify a timing constraint responsively to the first and second oscillating frequencies.