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:
Mar. 21, 2000
Filed:
Dec. 30, 1997
Terence G Blake, Dallas, TX (US);
Bernhard H Andresen, Dallas, TX (US);
Frederick G Wall, Garland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
According to one embodiment of the present invention, an output buffer (200) includes a first output driver (86) having a gate oxide protected from voltage changes on an output (16). A second output driver (88) also has a gate oxide protected from voltage changes on the output (16). A level shifter (60) includes at least one cascode device (66, 68, 70, 72) and switches the first output driver (86) according to the values of a data input (12) and an enable input (14). A bias-generation circuit (300) generates a quasi-failsafe voltage that is approximately equal to a chip core voltage when a power supply (4) is supplying the chip core voltage and equal to a portion of the chip core voltage when the power supply (4) is not supplying the chip core voltage. The bias-generation circuit (300) is coupled to a first output cascode (80) coupled to the first output driver (86), to a second output cascode (84) coupled to the second output driver (88), or to the cascode device (66, 68, 70, 72) of the level shifter (60).