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:
Jul. 03, 2001
Filed:
Jul. 28, 1999
Michael J. Shay, Arlington, TX (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A driver circuit implemented in an integrated circuit for driving an output node, typically connected to another integrated circuit. The driver circuit includes a control section which produces a digital control output indicative of the state of the process used to manufacture the integrated circuit. One or more driver sections, each connected to an output node of the integrated circuit, receive the digital control output and use the output to control the state of a transistor array connected between the associated output node and circuit common. The transistor array includes an offset transistor having a channel width to channel length ratio W,/L,and a multiplicity of adjust transistors, designated first through N, having respective channel width to channel length ratios (W,/L,),approximately equal to (W,/L,) (1+&Dgr;),where &Dgr; is a fixed weighted value less than one, such as 0.1. Based upon the digital control output, select circuitry is used to control the impedance between the output node and circuit common by selecting a number of the adjust transistors, with the number ranging from none to N.