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:
Oct. 01, 1991
Filed:
May. 29, 1990
Hitachi, Ltd., Tokyo, JP;
Abstract
In a high prrecision PLL circuit arrangement, a phase detecting circuit produces a detecting signal which is directly proportional to a phase difference between a horizontal synchronizing signal and a voltage-controlled oscillating signal. A loop filter circuit produces a delay signal for delaying a frequency control at a predetermined time constant in response to the detecting signal derived from the phase detecting circuit. A voltage-controlled oscillating circuit produces an oscillating signal having a frequency directly proportional to a voltage of the delay signal from the loop filter circuit. A non-linear circuit includes a non-linear element for changing at least one of an AC gain and a DC gain of the loop filter circuit, and prevents an erroneous capture phenomenon of the PLL circuit arrangement in response to the detecting signal from the phase detecting circuit.