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.

Date of Patent:
Dec. 17, 1996

Filed:

Feb. 02, 1996
Applicant:
Inventor:

Donald G Tipon, San Diego, CA (US);

Assignee:

NCR Corporation, Dayton, OH (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; H03K / ;
U.S. Cl.
CPC ...
326 26 ; 326 30 ; 326 86 ; 326121 ;
Abstract

In a high speed digital computer data transfer system, a data bus driver, implemented using complementary metal-oxide-semiconductor (CMOS), reduces data bus voltage swings between logic high and logic low levels by defining minimum and maximum bus voltages which lie between said logic levels, thus lowering bus transition and hence data transfer times. Voltage overshoot and undershoot of the reduced bus logic levels are prevented by two 'clamping diode' transistors. One of the two clamping diodes connected to the data bus is biased to a point just below conductivity, while the second clamping diode is biased to a point just below conductivity. As a result, if the output voltage rises above a selected level, the first clamping transistor acts as a conducting diode to pull the output voltage down, and, in a similar manner, if the output voltage at node falls below a selected level, then the second clamping transistor functions as a conducting diode to pull the output voltage up to an acceptable level.


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