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. 17, 2013
Filed:
May. 28, 2010
Yusaku Katsube, Yokohama, JP;
Junichi Takahashi, Yokohama, JP;
Masaaki Yamada, Yokohama, JP;
Toshihito Habuka, Tamamura, JP;
Kenichi Shibata, Takasaki, JP;
Fumihito Yamaguchi, Maebashi, JP;
Yusaku Katsube, Yokohama, JP;
Junichi Takahashi, Yokohama, JP;
Masaaki Yamada, Yokohama, JP;
Toshihito Habuka, Tamamura, JP;
Kenichi Shibata, Takasaki, JP;
Fumihito Yamaguchi, Maebashi, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
Gain setting can be performed at high speed while reducing DC offset due to a filter cutoff frequency changeover without the need for input signal muting. A filter circuit having first and second filters is capable of allowing settings of first and second cutoff frequencies. First and second filter switch circuits and a charging circuit including a charging resistor and a charging switch are provided. For a first time period, the first switch circuit is controllably turned on while the second switch circuit is controllably turned off, thereby providing the first filter function. For a second time period, the first switch circuit is controllably turned off while the second switch circuit is controllably turned on, thereby providing the second filter function. For the first time period, the charging switch is controllably turned on so that the second capacitor is charged via the charging resistor.