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:
May. 22, 1990
Filed:
Aug. 27, 1987
Steven P Marshall, Missouri City, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A CMOS push-pull output buffer is disclosed, which utilizes two reference nodes in the pull-down side. A first of the reference nodes is dedicated to switching the output from a high to a low logic state. A switching circuit is provided for driving the pull-down transistor associated with the first reference node responsive to the input node transition, but which turns off this pull-down transistor responsive to the output node approaching its final voltage. The second reference node is dedicated for holding the output node low in the DC state. A drive circuit is provided for driving the pull-down transistor associated with this second reference node, but which does not turn on this pull-down transistor until the output node has approached its final voltage, preferably when the first pull-down transistor is turned off. By controlling the turning on of the second pull-down transistor responsive to the output voltage, the coupling of noise from the first reference node to the second reference node can be minimized.