Differential line compensation apparatus, method and system

A differential line compensation method comprising:

• determining a first condition of at least one of a first signal and a second signal, the first signal being at least related to a first differential signal supplied by a first trace and the second signal being at least related to a second differential signal supplied by a second trace;
• determining a second condition of at least one of the first signal and the second signal;
• comparing the first condition and the second condition to give a control output;
• and
• using the control output to cause a delay to a selected one of the first signal and the second signal.

A semiconductor chip comprising:

• a first terminal to receive a first differential signal from a first trace of a differential line;
• a second terminal to receive a second differential signal from a second trace of the differential line;
• and
• a delay controller coupled to the first and second terminals to shift a phase of at least one of the first and second differential signals based on a delay of received first and second differential signals to compensate for differences in length of the first and second traces, wherein the delay controller to shift the phase is implemented by an analog circuit.

A differential line compensation system comprising:

• a printed circuit board comprising a pair of differential line traces;
• and
• a semiconductor chip mounted to the printed circuit board, the semiconductor chip comprising:
• a first terminal to receive a first differential signal from a first trace of a differential line;
• a second terminal to receive a second differential signal from a second trace of the differential line;
• and
• a delay controller coupled to the first and second terminals to receive the first and second differential signals and to shift the phase of at least one of the first and second differential signals based on a delay of the received first and second differential signals to compensate differences in length of the first and second traces, wherein the delay controller is implemented by an analog circuit.

A differential line compensation apparatus comprising:

• a first terminal to receive a first differential signal supplied by a first trace and a second differential signal supplied by a second trace;
• at least one detector to detect a first condition of a first signal related to the first differential signal, and a second condition of a second signal related to the second differential signal, and to provide at least one output containing results of the detections;
• a comparator coupled to the at least one detector to receive and process the at least one output and to provide a control output;
• and
• at least one delay controller to receive the control output and apply a phase correction to a selected one of the first signal and the second signal;
• wherein the first condition is a first voltage level of a first crossing of the first signal and the second signal, and the second condition is a second voltage level of a second crossing of the first signal and the second signal;
• and
• wherein the at least one detector comprises a first transistor and a second transistor, the first and second transistors having a common node, the first signal being able to be applied to a gate of the first transistor and the second signal being able to be applied to a gate of the second transistor.

A differential line compensation apparatus comprising:

• a first terminal to receive a first differential signal supplied by a first trace and a second differential signal supplied by a second trace;
• at least one detector to detect a first condition of a first signal related to the first differential signal, and a second condition of a second signal related to the second differential signal, and to provide at least one output containing results of the detections;
• a comparator coupled to the at least one detector to receive and process the at least one output and to provide a control output;
• and
• at least one delay controller to receive the control output and apply a phase correction to a selected one of the first signal and the second signal,
• wherein the first signal is the first differential signal and the first condition is a zero threshold of the first signal, and wherein the second signal is the second differential signal, the second condition being a zero threshold of the second signal.

A differential line compensation apparatus comprising:

• a first terminal to receive a first differential signal supplied by a first trace and a second differential signal supplied by a second trace;
• at least one detector to detect a first condition of a first signal related to the first differential signal, and a second condition of a second signal related to the second differential signal, and to provide at least one output containing results of the detections;
• a comparator coupled to the at least one detector to receive and process the at least one output and to provide a control output;
• and
• at least one delay controller to receive the control output and apply a phase correction to a selected one of the first signal and the second signal;
• wherein the at least detector comprises two detectors comprising a first detector and a second detector, and wherein the at least one delay controller comprises two delay controllers comprising a first delay controller operatively connected to the first terminal to receive the first differential signal and apply a first delay to the first differential signal to form the first signal, and a second delay controller operatively connected to the second terminal to receive the second differential signal and apply a second delay to the second differential signal to form the second signal, the first delay controller being operatively connected to the first detector to supply the first signal to the first detector, and the second trace is operatively connected to the second detector to supply the second signal to the second signal to the second detector.