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:
Jul. 30, 2013
Filed:
Feb. 02, 2012
Nobuo Takahashi, Gunma-ken, JP;
Toru Dan, Gifu-ken, JP;
Masashi Aramomi, Gunma-ken, JP;
Yoshiyasu Kaneko, Fukaya, JP;
Nobuo Takahashi, Gunma-ken, JP;
Toru Dan, Gifu-ken, JP;
Masashi Aramomi, Gunma-ken, JP;
Yoshiyasu Kaneko, Fukaya, JP;
Semiconductor Components Industries, LLC, Phoenix, AZ (US);
Abstract
The present invention quickly detects an offset and prevents cutoff of low frequency signals. Offset detection circuits smooth an output of a variable gain amplifier at a predetermined time constant and detects the offset, which is a DC component. The detected offset is added to the input of the variable gain amplifier by an adder and the offset in the output of the variable gain amplifier is corrected. The time constant in the offset detection circuit is changed by the resistance values of the variable resistors. Then, the time constant is changed to a small time constant when the gain of the variable gain amplifier is changed and thereafter to a large time constant.