Automatic de-emphasis setting for driving capacitive backplane

摘要

In described embodiments, automatic de-emphasis setting is provided for driving a capacitive backplane. Line impedance and line length of a transmission (TX) device are measured that form a load impedance of a driver. For some exemplary embodiments, the line impedance is predominantly a line capacitance, and such embodiments detect this capacitance. Measured line impedance is converted to a control signal (such as, for example, a three bit digital control signal) which automatically sets the de-emphasis of the TX stage. With the amount of capacitance and the length of the transmission line, the appropriate de-emphasis settings might be determined, and such de-emphasis setting be applied by the transmitter to the driver to compensate for transmission line effects.