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:
Sep. 02, 1986
Filed:
Mar. 25, 1985
Hisashi Takaki, Tokyo, JP;
Fumio Matsushita, Tokyo, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A phase-locked loop modulation circuit, such as may be used for a data communications purposes, in which undesired level variations are eliminated by employing d.c. coupling entirely. The circuit includes a level converter circuit which converts a logic signal into a signal having substantially equal levels above and below a predetermined voltage, a voltage-controlled oscillator, and a circuit for superposing the signal having substantially equal levels on a control voltage of the voltage-controlled oscillator so that the output of the voltage-controlled oscillator is subjected to angular modulation. In accordance with the invention, the level converter circuit includes a pair of voltage dividing resistors which divide the supply voltage, a pair of series circuit each composed of a resistor and a switch element connected in parallel with each of the series circuits being connected in parallel to a respective one of the pair of voltage dividing resistors, and a gating circuit for complementarily operating the switch elements on and off in accordance with the logic outputs signal.