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:
Feb. 02, 2016
Filed:
Sep. 12, 2014
International Business Machines Corporation, Armonk, NY (US);
Kai Di Feng, Hopewell Junction, NY (US);
David R. Hanson, Brewster, NY (US);
Chengwen Pei, Danbury, CT (US);
Ping-Chuan Wang, Hopewell Junction, NY (US);
International Business Machines Corporation, Arrmonk, NY (US);
Abstract
An on-chip frequency calibration apparatus is described. A ring oscillator generates a clock signal. A trimmable resistor is coupled to the ring oscillator. A frequency detector detects the frequency of the clock signal generated from the ring oscillator. The frequency detector includes a frequency divider component that divides the frequency of the clock signal by a predetermined number to derive an output signal having a pulse duration that is equal to at least one period of the clock signal, a capacitor, a capacitor charging current source, and a capacitor charge transistor directs a charging current generated from the capacitor charging current source to the capacitor as a function of the output signal generated from the frequency divider component. A resistor trimming unit trims the trimmable resistor in response to determining that the frequency detected by the frequency detector is less than a target frequency threshold.