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:
Jul. 07, 1998
Filed:
Jul. 29, 1997
Carl E Wojewoda, Lake Zurich, IL (US);
James F Caruba, Bartlett, IL (US);
Richard N Sutliff, Hampshire, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A temperature compensation circuit (10) for a crystal oscillator module (12) used in a communication device (200). An existing microcontroller (210) of the communication device (200) is used to provide temperature compensating digital data (30) for a crystal oscillator (18). The temperature compensating digital data (30) is converted to a temperature compensation signal (22) in a digital-to-analog converter (32) which controls the crystal oscillator frequency. The crystal oscillator module (12) includes an onboard voltage regulator (34) which supplies a characterized regulated voltage (36) to the digital-to-analog converter (32) such that the temperature compensation signal (22) from the digital-to-analog converter (32) is inherently corrected for voltage variations in the voltage regulator (34). Changes in the temperature compensation of the crystal oscillator (18) are allowed only when the communication device (200) is not transmitting or receiving.