Current-mode active termination

A termination circuit, comprising:

• a resistor having a first end and a second end, the first end coupled to an output terminal of a power transmitter circuit;
• a first controlled current source having first, second, and third terminals, the first terminal coupled to an input signal of the power transmitting circuit, the second terminal coupled to the second end of the resistor, and the third terminal coupled to ground;
• and
• a second controlled current source having first, second, and third terminals, the first terminal coupled to the second end of the resistor, the second terminal coupled to the output terminal of the power transmitter circuit, and the third terminal coupled to ground,
• wherein the resistor and the first controlled current source are configured such that zero current flows through the second controlled current source.

A device, comprising:

• a transmitter configured to generate an output current based on an input signal;
• a load, having a load impedance, coupled to an output terminal of the transmitter;
• and
• an active termination circuit, coupled to the output terminal of the transmitter, the active termination circuit comprising:
• a first current source, controlled by the input signal configured to draw a portion of the output current of the transmitter;
• and
• a second current source configured to have an output impedance, determined at the output terninal of the transmitter, that is substantially equal to the load impedance.