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:
Sep. 25, 2001
Filed:
Sep. 20, 1999
Michael A. Ang, San Francisco, CA (US);
Alexander D. Taylor, Olga, WA (US);
Jonathan E. Starr, Cupertino, CA (US);
Sai V. Vishwanthaiah, Sunnyvale, CA (US);
Sun Microsystems, Inc., Palo Alto, CA (US);
Abstract
A dynamic termination logic driver, the driver capable of launching signals at a driving end of a transmission line and terminating signals at a receiver end of the transmission line, controls slew rate over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit having an impedance, the pull up circuit including a pull up output circuit and a buffer circuit, the pull up output circuit including a parallel pull up circuit, a pull up output control circuit, and a pull up slew rate control circuit, wherein the parallel pull up circuit and the pull up output control circuit are coupled in parallel. The driver also includes a pull down circuit having an impedance, the pull down circuit including at least one pull down output circuit, the at least one pull down output circuit including at least one pull down slew rate control circuit, a parallel pull down circuit and a pull down output control circuit, wherein the parallel pull down circuit and the pull down output control circuit are coupled in parallel. The driver also includes a plurality of output elements within the pull up circuit and the pull down circuit, wherein the plurality of output elements are selectively enabled and disabled with a controlled slew rate. The selective enabling and disabling is based on an impedance control code.