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. 09, 1997
Filed:
Dec. 20, 1995
Delbert Raymond Cecchi, Rochester, MN (US);
Curtis Walter Preuss, Rochester, MN (US);
Donald Joseph Schulte, Eagan, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A full-duplex, differential, bi-directional communications link for simultaneously transmitting differential data between electronic devices is provided. Each transceiver coupled to the communications channel comprises a CMOS (Complementary Metal-Oxide Semiconductor) differential driver and receiver. The differential driver provides constant CMOS voltage sources for providing stable data signal transmission at reduced voltage levels. Voltage sources providing a data signal voltage different from the desired data signal voltage can be placed into a high impedance mode to allow the desired data signal voltage to be transmitted on the common line. The differential receiver includes self-biasing feedback circuitry to provide biasing voltages to the circuit while avoiding manufacturing difficulties associated with providing precise bias voltages. The complementary amplifier structure of the receiver provides an increased common mode noise tolerance. The receiver further includes signal separation circuitry to separate the desired recipient signals on the communications channel from those signals which are driven to another differential receiver.