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. 25, 2003
Filed:
Mar. 25, 2002
Applicant:
Inventor:
Wayne A. Tangen, Meridian, ID (US);
Assignee:
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K 1/9075 ;
U.S. Cl.
CPC ...
H03K 1/9075 ;
Abstract
A two-wire serial bus allows bus mastering by any device on the bus utilizing bus pull-ups. In systems with long bus lengths or large numbers of devices, rise times suffer unless accelerated. An operational amplifier (Op Amp) controlled current source is utilized to provide pull-up current for bus lines. The Op Amp provides precise control of the current value and the slew rate required to meet stringent demands of the two-wire serial bus. A voltage divider sets the input voltage to the Op Amp, and a transistor gates the Op Amp current to the bus until it saturates.