Longitudinal balance calibration for a subscriber line interface circuit
AssigneeSilicon Laboratories Inc.
InventorsMichael J. Mills, Marius Goldenberg, Alan F. Hendrickson, Ion C. Tesu, Jiangtao Yi
Life of this patent
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Abstract
A method of calibrating longitudinal balance for a subscriber line interface circuit includes providing a first and a second driver of a differential driver pair for driving a subscriber line. An output of each of the first and second drivers is coupled to a common output. The common output is coupled to an input of the first driver. The gain of at least one of the first and second drivers is adjusted until a calibration signal (V1) present at the input of the first driver is substantially the same as a calibration signal (V2) present at the input of the second driver.
Claims24
A method comprising:
- (a) providing a first and a second driver of a differential driver pair for driving a subscriber line, wherein an output of each of the first and second drivers is coupled to a common output, wherein the common output is coupled to an input of the first driver;
- (b) adjusting a gain of at least one of the first and second drivers until a calibration signal (V1) present at the input of the first driver is substantially the same as a calibration signal (V2) present at the input of the second driver, wherein the calibration signal present at the input of the first driver and the calibration signal present at the input of the second driver have a dominant spectral component.
An apparatus comprising:
- a first and a second driver of a differential driver pair for driving a subscriber line, wherein an output of each of the first and second drivers is coupled to feed a common output, wherein the common output is fed back to an input of the first driver;
- and
- a signal processor coupled to adjust a gain of at least one of the first and second drivers until a calibration signal (V1) present at the input of the first driver is substantially the same as a calibration signal (V2) present at the input of the second driver, wherein the calibration signal present at the input of the first driver and the calibration signal present at the input of the second driver have a dominant spectral component.
Dependencies are inferred from the claim text.