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:
Aug. 19, 1997
Filed:
May. 16, 1996
David W Millen, Yorkville, IL (US);
Carl Wojewoda, Lake Zurich, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A substantially sealed frequency source (10) including a crystal oscillator (14) and a programmable IC (22) thermally and electrically coupled on a substrate (12). The IC (22) is accessed through an interface (26) with programming signals (42) so as to provide an analog temperature control signal (34) and a crystal oscillator frequency adjustment signal (36). The substrate (12) maintains a substantially constant temperature at a turning point (82) on a frequency-temperature response curve (80) of the crystal (64). The IC (22) allows programming of the source (10) after sealing to compensate for shifts in the crystal frequency-temperature response (80) due to sealing. The IC (22) provides electrical correction of the substrate temperature setpoint and the crystal oscillator frequency without mechanically or thermally disturbing the internal components of the source (10).