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:
Nov. 24, 1998
Filed:
Apr. 08, 1998
Hideharu Koike, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A voltage subtracter circuit of the present invention includes a constant current source 1, a first MOS transistor pair 2, one end of which is connected to a source voltage terminal, and a second MOS transistor pair 3, one end of which is connected to the constant current source 1. A first differential input voltage is applied between the gate terminals of the first transistor pair 2, and a second differential input voltage is applied between the gate terminals of the second transistor pair 3. Output terminals V1 and V2 are connected to the connecting point between the first and second transistor pairs 2 and 3. From these nodes V1 and V2, a differential voltage between the first differential input voltage and a differential voltage proportional to the second differential input voltage is outputted. According to the present invention, this voltage subtracter circuit does not have any resistors, so that the circuit can be easily integrated and operated with high accuracy without being influenced by Vth and so forth.