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. 08, 2004
Filed:
Aug. 28, 2002
Jing-Meng Liu, Hsinchu, TW;
Kent Hwang, Taoyuan Hsien, TW;
Chao-Hsuan Chuang, Hsinchu, TW;
Cheng-Hsuan Fan, Hsinchu Hsien, TW;
Richtek Technology Corp., Hsinchu Hsien, TW;
Abstract
A resistance adjustable of resistance mirror circuit having a master resistor R , a reference current source terminal providing a current value I through the master resistor R to ground; a first transistor; a current mirror source terminal providing a current value n I , through the first transistor to ground; an operational amplifier having a positive terminal connecting to a drain of the first transistor, a negative terminal connecting to the other terminal of the master resistor R , and an output terminal connecting to a gate of the first transistor; a mirror resistor set composed of a plurality of transistors in parallel each other and having their source electrode connecting to ground. Each transistor of the mirror resistor set has a ratio of channel width over channel length being m-fold of that of the first transistor, where m, n is any positive numbers. Since gates of the transistors connect to the output terminal of the operational amplifier, each of the transistors therefore has an equivalent resistance R =(1/nm)R .