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:
Jun. 30, 2009
Filed:
Jan. 24, 2007
Hiroshi Tsuchi, Tokyo, JP;
Masao Iriguchi, Tokyo, JP;
Hiroshi Tsuchi, Tokyo, JP;
Masao Iriguchi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A differential amplifier comprises first, second, and third input terminals (and), output terminal (), first and second differential pairs (and) (and) driven by a corresponding current source and having output pairs commonly connected to load circuits (and), and an amplifier stage () having input end connected to at least one of the common connection points of the load circuits and output pairs of the first and second differential pairs and output end connected to output terminal. Input pair of second differential pair receives a signal from third input terminal and a feedback signal from output terminal. First and second switches (SWand SW) are provided between the input pair of the first differential pair and the first and second input terminals (and), and first and second capacitors (Cand C) connected between each connection point of the input pair of the first differential pair and the first and second switches (SWand SW) and a reference voltage terminal are provided. The first, second and third input terminals (and) may be combined into one terminal to which voltages are serially supplied. It avoids the influence of power supply/signal noise and switch noise, and provides operational output from a plurality of input reference voltages.