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.

Date of Patent:
Oct. 16, 2001

Filed:

Jul. 09, 1999
Applicant:
Inventors:

Daisuke Yamazaki, Kanagawa, JP;

Seiichi Ozawa, Kanagawa, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 3/45 ;
U.S. Cl.
CPC ...
H03F 3/45 ;
Abstract

DC components are removed by a first and a second capacitor from a normal signal and its inverted signal from a first and a second input terminal, and the signals are input to a DC level generating circuit. The DC level generating circuit newly adds a DC component to the respective signals from which the DC components are removed by the first and the second capacitors, and extracts only a DC voltage from a feedback voltage with a low-pass filter using the fist and the second capacitors. The circuit of the DC level generating circuit which includes the low-pass filter using the first and the second capacitors is configured so that a high-frequency cut-off frequency other than that included into a loop gain by the low-pass filter is not included. Consequently, only one high-frequency cut-off frequency exists in the loop gain, thereby preventing a feedback circuit from oscillating.


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