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:
Oct. 08, 1985
Filed:
Jan. 28, 1983
Applicant:
Inventor:
Toshiro Okada, Machida, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03L / ;
U.S. Cl.
CPC ...
331 17 ; 331 / ; 331 25 ;
Abstract
A phase-locked loop circuit comprises a voltage-controlled oscillator (11), a phase comparator (13), a low-pass filter (15), a plurality of pump circuits (14S, 14F, . . . ), and a selecting circuit (G.sub.45) for selecting one of the pump circuits. The low-pass filter is comprised of a capacitor (C) and a plurality of resistors (R.sub.1 to R.sub.3) each connected to one of the pump circuits. By selecting one of the pump circuits to connect to a corresponding resistor, the cutoff frequency or time constant of the low-pass filter is switched in multi-steps.