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. 13, 1995
Filed:
Mar. 31, 1994
Roger Van Brunt, San Francisco, CA (US);
Florin Oprescu, Sunnyvale, CA (US);
Apple Computer, Inc., Cupertino, CA (US);
Abstract
The level shifter provides a selective voltage level shift to a common mode signal level on a twisted pair signal line. The level shift is selectively performed based upon the input level of the common mode voltage. The level shifter is advantageously employed in a low voltage circuit wherein lacking sufficient voltage head room to accommodate a constant common mode level shift. An exemplary embodiment is described wherein the level shifter is employed within a bus transceiver of a bus system employing IEEE P1394 bus protocol. In the exemplary embodiment, the selective level shift is applied only to bus signals occurring during an idle phase and an arbitration phase, with no level shift performed during a data phase.