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:
Jun. 09, 1992
Filed:
Jun. 28, 1991
Applicant:
Inventor:
Russell W Brown, Nepean, CA;
Assignee:
Digital Equipment Corporation, Maynard, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L / ;
U.S. Cl.
CPC ...
331-8 ; 331 10 ; 331 17 ; 331 25 ; 360 371 ; 360 51 ;
Abstract
Separate charge pumps (58, 60 and 74, 76) drive integral and proportional control paths for a voltage-controlled oscillator (52) in a phase-locked loop (50). A control circuit (74) varies the loop gain of the phase-locked loop by varying the current supplied by the integral-path charge pump (58,60) through a range that is the square of the range through which the current supplied by the proportional-path charge pump (74, 76) is varied. As a consequence, the damping factor of the loop response changes very little as the loop gain is varied through a large range.