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. 17, 1980
Filed:
Aug. 14, 1978
William B Fazakerly, Saratoga, CA (US);
Daniel R Hafeman, Sunnyvale, CA (US);
Scientific Micro Systems, Inc., Mountain View, CA (US);
Abstract
A second order filter signal is derived in response to a phase comparison of two signals by selecting an input voltage from a reference voltage, a first voltage potential higher than the reference voltage, and a second voltage potential lower than the reference voltage depending on the phase error of the two signals. The input signal is applied to a loop filter including a non-inverting integrator and to a feed forward circuit. The outputs of the amplifier and feed forward circuit are summed and applied to an output terminal as the second order filter signal. An improved phase locked oscillator circuit is provided in which a digital phase comparator drives an active loop filter including a feed forward circuit and a non-inverting integrator.