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:
Dec. 29, 1998
Filed:
Nov. 20, 1996
Hwang-Cherng Chow, Chutung, Hsinchu, TW;
Other;
Abstract
In a preferred embodiment of the present invention an output buffer includes high current drivers that avoids a short circuit current. Further, the inventive output buffer only produces a slight level of ground bounce (noise). In particular, the buffer comprises first and second drivers for driving a terminal to a voltage corresponding to a high logic value of a first output signal and a low logic value of a second output signal, respectively. Typically, the first driver includes a plurality of PMOS pull-up transistors and the second driver includes a plurality of NMOS pull-down transistors. In addition, first and second predriver circuits, connected to the first and second drivers, respectively, are included. In operation, the first predriver receives the complement (inverse) of the first output signal and a delayed output of the second predriver. The second predriver receives the complement of the second output signal and the delayed output of the first predriver. In this manner, all pull-up (or pull-down) transistors are completely turned on before the pull-down (or pull-up) transistors are sequentially turned off. Therefore, a short-circuit current that may occur during a logic transition in the output signal is eliminated.