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:
Dec. 31, 1985
Filed:
Dec. 13, 1983
Kenji Nagai, Kodaira, JP;
Fumiaki Fujii, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An amplifier comprising a pair of differential input MISFETs, a current mirror circuit connected between the drains of the differential input MISFETs and a power source terminal, a phase compensation circuit connected to the drain of one of the differential input MISFETs, an output stage amplification circuit amplifying the signal produced at the drain of one of the differential input MISFETs, a phase regulation circuit such as a capacitor connected to the other of the differential input transistors, and a feedback circuit feeding back the output signal produced from the output stage amplification circuit to the other of the differential input MISFETs in order to apply negative feedback to the amplifier. Since the capacitor is provided, the phase of the power source noise can be made substantially equal to the phase of noise occurring at the drain of one of the differential input MISFETs due to the power source noise. Hence, hardly any noise is produced from the output stage amplification circuit. Since feedback is applied to the amplifier, the noise occurring at the drain of the other of the differential input MISFETs operates in such a manner as to limit the amount of change of the drain voltage of one of the differential input MISFETs due to the noise. As a result, a large change of the output signal due to the power source noise can be prevented. Furthermore, since an element to be added for this purpose may be merely a capacitor, a significant increase in the number of circuit elements can be avoided.