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:
Aug. 20, 1996
Filed:
Nov. 29, 1994
Tamotsu Suzuki, Kyoto, JP;
Yoshikazu Shimada, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A low-pass passive filter is inserted in the phase locked loop of a voltage-controlled oscillating circuit having a varactor diode. The filter has a first resistor, a capacitor and a second resistor connected in that order and the blocking characteristics of the filter are changed in accordance with a selected value of the second resistor. A push-pull output circuit in which the upstream transistor is connected directly to the supply voltage line receives the signal from a phase comparator circuit (which is indicative of the result of phase comparison) and outputs it to the low-pass passive filter. The low-pass passive filter controls the terminal voltage of the varactor diode in accordance with the terminal voltage of the capacitor and the value of the second resistor is selected depending on the desired blocking characteristics of the filter.