Method, device and system for output impedance calibration that invariably maximizes hybrid performance

An output impedance calibration method for invariably maximizing hybrid performance, said method comprising one or more steps selected from the group consisting of:

• a) calibrating an adjustable resistor R1 by
• disabling a replica digital-to-analog converter (DAC) current K;
• transmitting constant current (DC) from a main DAC;
• measuring an input peak amplitude Apeak—1 at a receiver;
• transmitting random data within a time constraint;
• and
• adjusting R1 until an input peak amplitude Apeak—i is on average half of Apeak—1, thereby matching R1 to a load impedance ZL;
• b) calibrating K for optimum DC matching in presence of ZL by
• enabling K;
• setting K to a nominal value;
• forcing a timing recovery loop such that said receiver and a corresponding transmitter are 180 degree out of phase, thereby forcing said receiver to sample hybrid output between transitions;
• and
• incrementing bias current in discrete steps until sampled hybrid output is minimized on average, thereby rendering an optimal K for ZL;
• and
• c) calibrating a slope-matching capacitor C2 by
• forcing said timing recovery loop such that said receiver and said transmitter are in phase;
• transmitting random data within a time constraint through both said main DAC and said replica DAC;
• observing sampled voltage at an input of said receiver;
• and
• adjusting C2 until voltage at said receiver input changes sign.