System and method to establish an adjustable on-chip impedance
OwnerRoy L. Vargasinventor
Life of this patent
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Abstract
A method to establish an adjustable on-chip impedance within a predetermined range that involves establishing a reference current for the adjustable on-chip impedance and applying this reference current to the adjustable on-chip impedance. A voltage produced by applying the reference current to the adjustable on-chip impedance is sensed and compared with the comparator or other similar processor to a reference voltage. This comparison allows the adjustable on-chip impedance to be tuned when the comparison of the sense voltage and the reference voltage is unfavorable. Tuning the impedance results in an impedance value within a predetermined range that accounts for variances of both the reference current and reference voltage.
Claims12
A method to establish an adjustable on-chip impedance within a predetermined range, the method comprises:
- establishing a reference current for the adjustable on-chip impedance;
- sensing a voltage produced by applying the reference current to the adjustable on-chip impedance;
- comparing the sensed voltage with a reference voltage;
- and
- tuning the adjustable on-chip impedance when the comparison of the sensed voltage and the reference voltage is unfavorable, such that an impedance value of the adjustable on-chip impedance is within predetermined range that accounts for variance of the reference current and the reference voltage.
A calibration circuit to establish an impedance value of an adjustable on-chip impedance within a predetermined range, comprising:
- a reference current source to provide a reference current, which is applied across the adjustable on-chip impedance;
- a comparator operably coupled to sense and compare a voltage generated across the adjustable on-chip impedance, and a reference voltage, and wherein the comparator provides an output that indicates when the comparison of the sensed voltage and the reference voltage is unfavorable;
- and
- a tuning module to receive the output of the comparator and to increment the adjustable on-chip impedance when the comparison of the sensed voltage and the reference voltage is unfavorable such that an impedance value of the adjustable on-chip impedance is within a predetermined range that accounts for variance of the reference current and the reference voltage.
Dependencies are inferred from the claim text.