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:
Mar. 27, 1990
Filed:
May. 16, 1989
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A voltage controlled oscillator (VCO) is controlled by a separate phase locked loop (PLL). The PLL includes a first variable delay circuit of m stages which receives a reference frequency signal and produces a delayed signal which is compared in a phase comparator with the reference frequency signal. A first control signal generating circuit in the PLL receives the output of the phase comparator and a reference voltage to produce a first control signal for controlling the delay of the first variable delay circuit. The VCO contains a ring oscillator formed of a second variable delay circuit of n stages similar to those of the first variable delay circuit. A second control signal generating circuit in the VCO receives the output of the phase comparator and a control voltage to produce a second control signal for controlling the delay of the second variable delay circuit to thereby control the output frequency of the VCO.