Voltage mode transmitter equalizer

A voltage mode transmitter equalizer has high efficiencies, yet consumes substantially constant supply current from the power supply and provides constant back-match impedance. The voltage mode transmitter equalizer is configured such that the output voltage of the signal to be output on a pair of transmission lines can be controlled according to the input data, but its return impedance is substantially matched to the differential impedance of the transmission lines and it draws substantially constant supply current from the power supply regardless of the output voltage of the signal. Further, an equalizer for a voltage-mode transmitter provides fine-granularity equalization settings by employing a variable pull-up conductance and a variable pull-down conductance. Conductance is varied by selectively enabling a plurality of conductance channels, at least some of which have resistance values that are distinct from one another.