Miscellaneous active electrical nonlinear devices – circuits – and – Specific identifiable device – circuit – or system – Unwanted signal suppression
Reexamination Certificate
2005-05-17
2005-05-17
Cunningham, Terry D. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Specific identifiable device, circuit, or system
Unwanted signal suppression
C327S555000
Reexamination Certificate
active
06894557
ABSTRACT:
An integrated circuit formed on a semiconductor chip, comprising a low pass filter circuit having a first resistor of a first resistance value and a capacitor of a first capacitance value, wherein the first resistance value and the first capacitance value determine a corner frequency of the filter; and a tuning circuit having a second resistor of a second resistance value, a switched-capacitor of a third resistance value and a comparator that compares two voltage signals to produce a control signal, wherein the control signal adjusts the first and second resistance values as a function of the third resistance value. The corner frequency of the filter can be adjusted by varying one or more reference voltage signals. In combination, the corner frequency of the filter is adjusted by changing the frequency of a clock that controls the switched-capacitor to decrease the circuit sensitivity.
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Chen Chun-Ying
Duncan Ralph A.
Shin Young J.
Broadcom Corporation
Cunningham Terry D.
Sterne, Kessler, Goldstein & Fox P.L.LC.
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