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:
Feb. 08, 1994
Filed:
Sep. 15, 1992
Takashi Tomatsu, Fuchu, JP;
Takaaki Noda, Higashimurayama, JP;
Hitachi, Ltd., Tokyo, JP;
Akita Electronics Co., Ltd., Akita, JP;
Abstract
An operational amplifier is equipped at its input stage with a folded cascode type differential amplifier and at its downstream stage with pre-buffers, which include a differential amplification stage of PMOS input and a differential amplification stage of NMOS input, as level shifters. A MOS resistor having its gate terminal fed with an intermediate bias potential between a supply voltage V.sub.DD and an earth potential is connected between every one of the drain terminals of current-mirror connected load MOSFETs in the pre-buffers. As a result, the gains of the pre-buffers in the steady state can be suppressed to about 10 dB or less. The individual MOSFETs of the push-pull output stage are individually driven by the pre-buffers of low gains.