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:
Nov. 24, 1981
Filed:
Jul. 09, 1979
Robert K Moulton, North Wales, PA (US);
John W Thompson, Willow Grove, PA (US);
Sperry Corporation, New York, NY (US);
Abstract
The output signal of a voltage-controlled oscillator of a phase-locked loop has its phase compared with the phase of incoming data in a phase detector producing a first signal. This first signal is then passed through a non-inverting amplifier to produce an amplified signal of the same polarity. The first signal is also passed through an inverting amplifier otherwise similar to the non-inverting amplifier to produce an amplified signal of opposite polarity. The inverted and non-inverted amplified signals are then filtered in respective low pass filter circuits and combined differentially in an amplifier which produces an error voltage for the voltage-controlled oscillator. Differential combining of the inverted and non-inverted amplified signals eliminates undesired D.C. voltage components caused by temperature drifts and the like by mutually cancelling such components while effectively doubling the amplitude of the desired error voltage.