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. 11, 1997
Filed:
Nov. 29, 1995
Kouichi Hasegawa, Tokyo, JP;
Kazuyuki Yuda, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor IC used for synthesizer having a phase locked loop PLL, a voltage controlled oscillator (VCO) and a mixer (MIX) for intermediate frequency is formed on a one chip silicon wafer. A semiconductor IC used for synthesizer having a VCO portion and an internal circuit such as PLL on a silicon wafer chip includes a differential buffer circuit which separates the VCO portion from the internal circuit. A capacitor (C1) is connected to an output of the VCO portion. A constant voltage source (V1) may be connected to respective input of the differential transistors (Q4, Q5). Transistors (Q6,Q7) provide emitter follower output circuits in the differential buffer. Respective emitters of the transistors (Q6,Q7) are connected to corresponding constant current sources (I1,I2).