Miscellaneous active electrical nonlinear devices – circuits – and – Gating – Delay controlled switch
Reexamination Certificate
2002-08-19
2004-06-08
Ton, My-Trang Nu (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Gating
Delay controlled switch
C327S170000
Reexamination Certificate
active
06747504
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to European Patent Application No. 01310739.6 filled on Dec. 20, 2001.
BACKGROUND OF THE INVENTION
This invention relates to controlling rise and fall times of a digital waveform, for example as produced by a line driver.
SUMMARY OF THE INVENTION
Often in the art, it is thought that digital waveforms should have rise (and fall) times that are as short as possible, and indeed in the idealised form of these waveforms that is often considered those times are taken to be zero. Short rise times mean, however that the waveform has large high frequency components and in some applications these can cause malfunctions in circuits receiving the waveforms. Also having large high frequency components can be undesirable when transmitting the waveform, particularly for example when the high frequencies travel at a different speed.
It is an object of the invention to produce a digital waveform with controlled rise and fall times. A further object is to make those times selectable.
A known way to control an edge in an output is described in the applicant's U.S. Pat. No. 6,215,816. That arrangement provides a local area network physical layer interface device for connection to an unshielded twisted pair cable. Each edge in an output is divided into a series of sub edges each provided by separate component drivers, each triggered in turn with small delays between them. Thus, the overall rise/fall time (across all the sub edges) is controllable via the delay between each of the sub edges. The device includes synthesised rise time control for reduced electromagnetic interference, (which again is produced by high frequency components). The twisted pair is driven by component drivers that are triggered to give their contribution to the signal edge by respective taps from a ring oscillator.
REFERENCES:
patent: 3916215 (1975-10-01), Gaskill, Jr. et al.
patent: 5220201 (1993-06-01), Kawasaki et al.
patent: 5444410 (1995-08-01), Polhemus
patent: 5521540 (1996-05-01), Marbot
patent: 5652533 (1997-07-01), Wong et al.
patent: 5942937 (1999-08-01), Bell
patent: 6054884 (2000-04-01), Lye
patent: 6134182 (2000-10-01), Pilo et al.
patent: 6219384 (2001-04-01), Kliza et al.
patent: 6259295 (2001-07-01), Kriz et al.
patent: 0 302 548 (1989-02-01), None
patent: 0 709 950 (1996-05-01), None
Forey Simon D.
Milton Jonathan P.
Simpson Richard D.
Brady III W. James
Nu Ton My-Trang
Stewart Alan K.
Telecky , Jr. Frederick J.
Texas Instruments Incorporated
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