Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Slope control of leading or trailing edge of rectangular or...
Reexamination Certificate
2011-08-23
2011-08-23
Cox, Cassandra (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Slope control of leading or trailing edge of rectangular or...
C327S108000
Reexamination Certificate
active
08004330
ABSTRACT:
Apparatus and methods modulate the slew rate of high-speed edges of a differential digital signal. High-speed digital signals carried over printed circuit boards, backplanes, cables, and the like can radiate electromagnetic waves. These electromagnetic waves can cause electromagnetic interference (EMI), and are tightly regulated by appropriate agencies, such as the FCC. Common mode radiation from differential signals can also cause EMI. By modulating the slew rates of the rising and falling edges of the differential signal, and by applying negative feedback, symbol-rate related spurs can be spread over a wider frequency range than conventional spread spectrum clocking (SSC) techniques, and thus should generally be capable of greater EMI reduction than conventional SSC techniques.
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Acimovic Predrag
Hernandez Richard Wayne
Mishra Parmanand
Cox Cassandra
Knobbe Martens Olson & Bear LLP
PMC-Sierra Inc.
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