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:
Jul. 11, 2000
Filed:
Jun. 22, 1998
Carol A Huber, Macungie, PA (US);
Bernard L Morris, Emmaus, PA (US);
Bijit T Patel, Breinigsville, PA (US);
Lucent Technologies, Inc., Murray Hill, NJ (US);
Abstract
CMOS technology is used to create a controlled output impedance output buffer circuit. An output buffer driver uses buffer circuits having impedance elements with linear characteristics. A control circuit uses a known impedance load to control the impedance of the buffer circuits. The control circuit monitors a known current flowing through the known impedance load to determine whether the output buffer circuit's output impedance needs to be adjusted to match a transmission line's impedance. Adjustments occur when the control circuit generates control signals to turn on or off various buffer circuits (and their impedance elements) contained within the output driver. In doing so, the output buffer circuit ensures that its output impedance will match the impedance of a transmission line over the entire range of output voltages regardless of the variations caused by the manufacturing process, operation temperature and power supply voltage.