Wave transmission lines and networks – Automatically controlled systems – Impedance matching
Reexamination Certificate
2000-07-20
2004-03-09
Pascal, Robert (Department: 2817)
Wave transmission lines and networks
Automatically controlled systems
Impedance matching
Reexamination Certificate
active
06703908
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to the field of electronics, and more particularly to an impedance controller for an electronic circuit.
BACKGROUND
Voltage, temperature, and processing causes the impedance of an output driver in an electronic circuit to vary. This variation can add noise, increase the power, and reduce the data transfer rate of the driver. In the prior art, variations in impedance due to environmental and processing parameters have been compensated for using analog circuitry, and in particular a low pass filter (LPF) to filter out a certain range of noise frequency. Such filters, however, are typically custom devices and are not available in most circuit design macro libraries. It is desirable, however, that a digital design be provided for this purpose, thus allowing the impedance compensating circuitry to be implemented with most macro libraries. Furthermore, there are other limitations in the art concerning impedance compensation that would be desirable to address, as discussed further below.
SUMMARY OF THE INVENTION
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Jenkins Philip N.
Ma Nan
Ruesch Rodney
Jones Stephen E.
Pascal Robert
Schwegman Lundberg Woessner & Kluth P.A.
Silicon Graphic, Inc.
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