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:
Apr. 11, 1995
Filed:
Mar. 30, 1994
Tatsuru Kojima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A frequency synthesizer, which realizes speed-up of channel switching between channels having separated frequencies, has an EEPROM which stores the phase difference between a first frequency divider and a second frequency divider producing outputs corresponding to the frequencies of the channels to be switched. A delay circuit delays the output of the second frequency divider by an amount corresponding to an amount of the phase difference stored in the EEPROM. A controller supplies the outputs of the second frequency divider and the delay circuit to a phase detector. Further, the controller stops a PLL operation and restarts it in synchronism with a leading edge of, preferably, a second period of the output signal of the reference oscillator to which the preset phase difference is given.