Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Having specific delay in producing output waveform
Reexamination Certificate
2008-06-24
2008-06-24
Cox, Cassandra (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Having specific delay in producing output waveform
C327S276000
Reexamination Certificate
active
07391251
ABSTRACT:
An adjustable-delay filter performs wave shaping to emulate pre-emphasis or de-emphasis of transmission-line signals. The adjustable-delay filter uses analog components and does not need a clock. The receiver does not have to recover a bit-clock from the data stream, eliminating a clock recovery circuit. An input buffer receives the input signal and drives current to a summer and to an adjustable delay. The adjustable delay inverts and delays the current and drives a delayed, inverted current to the summer. The summer combines the delayed, inverted current and the current from the input buffer to generate an output signal. The delay time of the adjustable delay can be programmed by a user and is less than the bit period. After a signal transition, the output signal initially spikes higher, then falls back to a nominal level after the delay time has expired. The initial signal spike emulates de-emphasis or pre-emphasis.
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Ngai Henry P.
Zhang Michael Y.
Auvinen Stuart T.
Cox Cassandra
g Patent LLC
Pericom Semiconductor Corp.
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