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:
Jan. 11, 2011
Filed:
Aug. 02, 2006
Kazuhisa Ishiguro, Ota, JP;
Yoshiaki Takahashi, Ora-machi, JP;
Kazuhisa Ishiguro, Ota, JP;
Yoshiaki Takahashi, Ora-machi, JP;
Ricoh Co., Ltd., Tokyo, JP;
Abstract
A differential amplifier circuit at the input stage is configured with a twin differential type having a first differential amplifier circuit () and a second differential amplifier circuit (), respective outputs of which are received by a first and a second source-grounded amplifier (M, M). The second source-grounded amplifier (M) is connected to a current mirror circuit (M, M), which is driven by the drain current of the second source-grounded amplifier (M). With this configuration, the dynamic range for the upper half portion of an alternating signal output from an output terminal (OUT) is determined by the current supply capability of the first source-grounded amplifier (M) and the dynamic range for the lower half portion is determined by the current supply capability of the second source-grounded amplifier (M). This eliminates the need of a constant current circuit of a large current for generating a signal having lower half portion in which the waveform distortion is improved.