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:
Nov. 18, 2014
Filed:
Dec. 24, 2013
Liming Xiu, Plano, TX (US);
Liming Xiu, Plano, TX (US);
Other;
Abstract
A Time-Average-Frequency direct period synthesizer is used to improve crystal-less frequency generator's frequency stability. It includes (a) a temperature sensor circuit to compensate temperature-induced frequency instability; (b) a voltage sensor circuit to compensate voltage-induced frequency instability; (c) a calibration circuit to correct manufacture-related frequency error; (d) a frequency control word update circuit to receive the temperature- and voltage-related frequency adjustments, and the calibration-related adjustment, to generate the corresponding frequency control word in a predetermined schedule; (f) a Time-Average-Frequency direct period synthesizer to receive said frequency control word in the predetermined schedule and produce a clock signal with a frequency that is stable and accurate by counteracting the frequency variation caused by crystal-less oscillators' temperature and voltage dependence and correcting the frequency error introduced in manufacture process. Methods of correcting crystal-less oscillators' frequency error and compensating its frequency variation are also disclosed.