Biased control loop circuit for setting impedance of output driver
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jul 23, 2002
Grant Date -
N/A
app pub date -
Sep 11, 2000
filing date -
Sep 11, 2000
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A biased control loop for setting the impedance of an output driver includes a dummy driver having a variable output impedance, a sample and compare circuit to compare the output impedance of dummy output driver to a reference, and an up/down counter to modify the impedance. When the loop is locked, an error signal alternates positive and negative about a reference value. A digital filter produces a filtered version of the error signal with an apparent error value that does not alternate. The digital filter has a biased lock circuit that guarantees that the apparent error does not alternate. A simultaneous bidirectional port includes an output driver and the biased control loop to set the output driver impedance. When the output driver drives a bidirectional line and serves as a termination impedance for another driver, the reduced apparent error variation provides improved impedance matching.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully