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:
Oct. 12, 1999
Filed:
Dec. 18, 1997
Ichiro Fujimori, Sagamihara, JP;
Asahi Corporation, , JP;
Abstract
An integrated circuit is provided for sourcing a mirrored current into a high impedance output node. A load may be coupled to the output node, and the mirrored current may be derived proportional to or substantially equal to current forwarded from a reference current source. The integrated circuit, or current mirror, includes a pair of series-connected output transistors coupled between the output node and a reference terminal. One of the output transistors is dimensioned with a channel that is short enough to ensure the threshold voltage of that transistor is smaller than the threshold voltage of the other transistor having a longer channel. Thus, one transistor utilizes the benefits of high density integrated circuit manufacture and, more specifically, short channel effects arising from channel length less than, e.g., 1.0 microns. The difference in threshold voltages between the pair of output transistors, and mutually connecting gates of those transistors helps maximize the output impedance and voltage swing from the output node of the current mirror while minimizing voltage needed to operate the current mirror.