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. 06, 2006
Filed:
Oct. 23, 2003
Yasushi Hayakawa, Tokyo, JP;
Yasushi Hayakawa, Tokyo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
A bias voltage generating circuit and a differential amplifier which can ensure a constant current through a constant current circuit in a differential amplifier circuit even in case that a common mode voltage of the reference voltage signal to the differential amplifier circuit changes are attained. A constant current is generated employing a current source (Isw) and a current mirror circuit composed of a transistor (Mand M). The constant current is supplied to a source of a transistor (M). A drain and a gate of a transistor (M) are connected with a drain of the transistor (M). A reference voltage signal (Vref) to a differential amplifier circuit is inputted to a gate of the transistor (M), and a drain potential of the transistor (M) is made to function as a bias voltage (biasn) to a constant current circuit in the differential amplifier circuit. Even if an absolute value of the reference voltage signal (Vref) changes, the bias voltage (biasn) has a feedback action ensuring the constant current through a constant current circuit.