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:
May. 21, 2013
Filed:
Jun. 11, 2010
Hiroki Kimura, Chitose, JP;
Hiroki Kimura, Chitose, JP;
Nihon Dempa Kogyo Co., Ltd, Tokyo, JP;
Abstract
A PLL circuit which can obtain a VCO output having satisfactory spurious output characteristics with respect to all channels and which can suppress the fluctuation of the characteristics due to a temperature change is disclosed. A control circuitprovides a frequency division ratio tablewhere frequency division ratios to improve spurious output characteristics in the output of a VCO for each channel number at temperatures are stored, and the control circuit reads, from the table, the frequency division ratio corresponding to the temperature detected by the temperature sensorand an input channel number, to set the frequency division ratio in a PLL ICand to set the channel number and the frequency division ratio in a DDS circuit. The DDS circuitcalculates the value of a reference frequency based on the channel number and the frequency division ratio to generate the reference frequency.