Method and apparatus for DC feed
AssigneeZarlink Semiconductor (U.S.) Inc.
InventorsMerle L. Miller, Jin Li
Life of this patent
Estimating the term…
Abstract
A method and apparatus is provided for DC feed control for a line card. The method includes determining if the line card is operating in a current limit region of a DC feed curve and synthesizing a curve in the current limit region. The method further includes determining a loop voltage based on the synthesized curve, and applying the loop voltage to the subscriber line. The apparatus includes logic capable of determining if the line card is operating in a current limit region of a DC feed curve and capable of determining a loop voltage based on a synthesized curve in the current limit region. The apparatus further includes circuitry for applying the loop voltage to the subscriber line.
Claims23
A method for DC feed control for a line card, comprising:
- using an analog-to-digital converter for processing voice signals;
- receiving a signal from a subscriber line;
- converting the signal to a digital signal using the analog-to-digital converter utilized for processing voice signals;
- and
- adjusting the DC feed control of the line card based on the digital signal.
A method for DC feed control for a line card, comprising:
- determining if the line card is operating in a current limit region of a DC feed curve;
- synthesizing a curve in the current limit region;
- determining a loop voltage based on the synthesized curve;
- and
- applying the loop voltage to the subscriber line.
A method for DC feed control for a line card, comprising:
- generating a current value proportional to a loop current flowing from a subscriber line;
- determining if the line card is operating in a current limit region of a DC feed curve in response to generating the current value;
- determining a loop voltage based on synthesizing a curve in the current limit region;
- and
- applying the loop voltage to the subscriber line.
An apparatus, comprising:
- logic capable of:
- determining if the line card is operating in a current limit region of a DC feed curve;
- and
- determining a loop voltage based on a synthesized curve in the current limit region;
- and
- a circuitry for applying the loop voltage to the subscriber line.
An apparatus, comprising:
- a first feedback loop, comprising:
- an analog-to-digital converter for converting a signal from a subscriber line to a digital signal;
- and
- first logic for receiving the digital signal and determining a cancellation current proportional to a current flowing from the subscriber line;
- and
- a second feedback loop, comprising second logic for adjusting a DC level control based on the determined cancellation current.
A line card, comprising:
- a digital signal processor capable of:
- determining if the line card is operating in a current limit region of a DC feed curve;
- and
- determining a loop voltage based on a synthesized curve in the current limit region;
- and
- a subscriber line interface circuit capable of applying the loop voltage to the subscriber line.
An apparatus, comprising:
- means for determining if a line card is operating in a current limit region of a DC feed curve;
- means for determining if the line card is operating in a current limit region of a DC feed curve in response to generating the current value;
- means for determining a loop voltage based on synthesizing a curve in the current limit region;
- and
- means for applying the loop voltage to the subscriber line.
Dependencies are inferred from the claim text.