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:
Aug. 11, 1998
Filed:
Aug. 26, 1996
Richard Francis Frankeny, Elgin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A reference generation and switched current source system suitable to convey data signals over a transmission line with minimum reflection through the use of active termination, transmission line current biasing, and the use of a shared referenced voltage derived from the characteristic impedance of the line as refined by integrated circuit transistor parameters at the transmitter and receiver. The integrated circuit chips connected by the transmission line each have a reference generator which defines a bias voltage for an active terminator, a bias current for injection into the transmission line, and a switched current source. The reference node interconnecting the transmitting and receiving devices conveys a voltage nominally twice the voltage at which the transmission line is biased and nominally twice the voltage increase introduced by the switched current source. The switched current source at the transmitting end, the bias current provided at the transmitting end, and the bias level of the active terminator at the receiving end of a transmission line are derived directly from the voltage on the reference node while compensating for the unique characteristics of the integrated circuit transistors in the respective chips.