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:
Jan. 20, 1981
Filed:
Feb. 02, 1979
Frederick Reisfeld, Commack, NY (US);
Burroughs Corporation, Detroit, MI (US);
Abstract
A phase-locked loop oscillator system includes a phase comparator in the form of a flip flop which is switched between states in response to received data pulses at one input and oscillator generated clocking pulses at another input. The positive and negative outputs of the flip-flop energize positive and negative constant current generators whose outputs feed in parallel a low pass filter or integrator including a capacitor which is initially discharged at the start of data reception by a field effect transistor connected in parallel with the capacitor. The output of the filter is a voltage whose amplitude is a measure of the phase difference between the sets of pulses. This voltage controls the amplitude of charging current fed to a sawtooth waveform generator to control the frequency thereof. The output of the generator is processed to form the clocking pulses for the system.