Inter-pair skew adjustment

A method of adjusting skew, the method comprising:

• receiving, by a skew detector, a plurality of signals from a cable coupled to a transmitter, the cable comprising at least one pair of differential signal conductors;
• detecting, by the skew detector, a skew amount between two of the plurality of signals, each of the two of the plurality of signals comprising a signal from a respective conductor of one pair of the differential signal conductors;
• providing, by an offset controller, a delay control signal based on the detected skew amount;
• extracting, by a common mode extraction circuit of a skew delay circuit, a common mode voltage between the two of the plurality of signals;
• and
• enabling one or more delay stages of the skew delay circuit according to the delay control signal and delaying at least one of the two of the plurality of signals with reference to the common mode voltage, and
• summing, by a summation circuit of the skew delay circuit, an output of the one or more delay stages, rejecting the common mode voltage from the output of the one or more delay stages, and providing an output of the skew delay circuit,
• wherein
• an adjusted skew between the two of the plurality of signals at the output of the skew delay circuit is less than the detected skew amount by an amount corresponding to the enabled one or more delay stages, and
• the two of the plurality of signals comprise positive and negative signals of a pair of differential signals.

An apparatus, comprising:

• means for receiving a plurality of signals from a cable coupled to a transmitter, the cable comprising at least one pair of differential signal conductors;
• means for detecting a skew amount between two of the plurality of signals that comprise positive and negative signals of a pair of differential signals, each of the two of the plurality of signals comprising a signal from a respective conductor of one pair of the differential signal conductors;
• means for providing a delay control signal based on the detected skew amount;
• means for extracting a common mode voltage between the two of the plurality of signals;
• means for enabling one or more delay stages according to the delay control signal and delaying at least one of the two of the plurality of signals with reference to the common mode voltage;
• and
• means for summing an output of the one or more delay stages, rejecting common mode voltage from the output of the one or more delay stages, and providing a skew delay output.

A method comprising:

• receiving a plurality of signals from a cable that couples to a transmitter and comprises a pair of differential signal conductors;
• detecting skew amount between two of the plurality of signals that comprise positive and negative signals of a pair of differential signals, each of the two of the plurality of signals comprising a signal from a respective conductor of the pair;
• providing a delay control signal based on the detected skew amount;
• extracting a common mode voltage between the two of the plurality of signals;
• enabling one or more delay stages according to the delay control signal and delaying at least one of the two of the plurality of signals with reference to the common mode voltage;
• and
• summing an output of the one or more delay stages and rejecting common mode voltage from the output.