Transmission line driver circuit for adaptively calibrating impedance matching

A transmission line driver circuit for adaptively calibrating impedance matching, comprising:

• a transmission line driving amplifier comprising a first transmission terminal and a second transmission terminal for providing a pair of differential transmission signals;
• a first signal node for coupling with a first load-end signal node of an equivalent load circuit;
• a second signal node for coupling with a second load-end signal node of the equivalent load circuit;
• a first adjustable resistor positioned on a signal path between the first transmission terminal and the first signal node;
• a second adjustable resistor positioned on a signal path between the second transmission terminal and the second signal node;
• an internal node;
• a first divider resistor, wherein a first terminal of the first divider resistor is coupled with a signal path between the first adjustable resistor and the first signal node, and a second terminal of the first divider resistor is coupled with the internal node;
• a second divider resistor, wherein a first terminal of the second divider resistor is coupled with a signal path between the second adjustable resistor and the second signal node, and a second terminal of the second divider resistor is coupled with the internal node;
• a comparing circuit, coupled with the internal node, configured to operably compare a reference voltage with a divided voltage at the internal node to generate a comparison signal;
• and
• an adjusting circuit, coupled with the first adjustable resistor, the second adjustable resistor, and the comparing circuit, configured to operably adjust resistance of at least one of the first adjustable resistor and the second adjustable resistor according to the comparison signal.