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. 02, 1992
Filed:
Jun. 27, 1990
Russell W Borwn, Nepean, CA;
Michael D Leis, Framingham, MA (US);
Elmer C Simmons, Whitman, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A multi-band processing system for automatically tuning the oscillator of a phase-locked loop to the frequency and phase of an applied input. The system includes an error detection circuit, a frequency controller, a scaling circuit, and a phase and frequency controller. The applied input and the oscillator output are coupled to the error detection circuit whose error output drives a charge pump/filter circuit. An error signal is derived from the difference between the loop charge pump output V.sub.1 and a preset charge pump zero error reference signal V.sub.ref, wherein the frequency controller regulates the oscillator output frequency according to a frequency error component of V.sub.1 -V.sub.ref, the scaling circuit scales the oscillator output frequency according to a system scaling signal N, and the phase and frequency controller adjusts the oscillator output frequency and phase according to V.sub.1 -V.sub.ref, when a 1/N multiple of the frequency of the oscillator output is compared in the error detection circuit to the frequency of the applied input.