Method and apparatus for a differential feedback in an active impedence feedback circuit

An apparatus, comprising:

• a voltage-to-current signal converter to convert a differential input voltage signal;
• a first buffer amplifier operatively coupled to said voltage to current signal converter, said first buffer amplifier to receive a component of a converted differential input signal on a first input terminal and produce a first buffered current signal;
• a first sense resistor operatively coupled with said buffered amplifier;
• a second buffer amplifier operatively coupled to said voltage-to-current signal converter, said second buffer amplifier to receive a component of said converted differential input signal on a second input terminal and produce a second buffered current signal;
• a second sense resistor operatively coupled with said second buffer amplifier;
• an active feedback impedance network operatively coupled with said first and second sense resistors;
• a first datasense amplifier operatively coupled to said active feedback impedance network and to said first sense resistor, said first datasense amplifier to generate a first and second component of a differential feedback signal;
• a second datasense amplifier operatively coupled to said active feedback impedance network and to said second sense resistor, said second datasense amplifier to generate a third and fourth component of said differential feedback signal;
• a first summing node for summing said first and second components of said differential feedback signal to generate a first component of a summed differential feedback signal for feedback into said first buffer amplifier;
• and
• a second summing node for summing said third and fourth components of said differential feedback signal to generate a second component of said summed differential feedback signal for feedback into said second buffer amplifier.

A system, comprising:

• a subscriber line;
• and
• a line card electronically coupled with said subscriber line, said line card being adapted to:
• receiving a signal;
• and
• performing a current feedback of an output signal in an active feedback synthesis mode based upon said signal, performing said active current feedback comprising using an active feedback network for conditioning an output signal, converting said signal into a differential current signal, and summing at least two components of said differential current signal for performing a differential feedback.