Low power low voltage differential driver

A differential communication circuit comprising:

• a differential receiver comprising:
• a positive input terminal;
• a negative input terminal;
• a positive transmission line coupled to the positive input terminal of the differential receiver;
• a negative transmission line coupled to the negative input terminal of the differential receiver;
• a terminating resistor coupled between the positive transmission line and the negative transmission line;
• and
• a differential transmitter comprising:
• a first power source configured to supply a first voltage;
• a second power source configured to supply a second voltage that is less than the first voltage;
• a current steering circuit coupled between the first power source and the second power source, the current steering circuit being configured to steer a current into either a positive differential output node or a negative differential output node to transmit a differential signal according to a data signal and a dataN signal;
• a resistor interposed between the first power source and the current steering circuit;
• and
• a constant current sink interposed between the current steering circuit and the second power source, the constant current sink being configured to sink the current having a substantially constant value,
• wherein the dataN signal is the inverse of the data signal,
• wherein the positive differential output node is coupled to the positive transmission line, and
• wherein the negative differential output node is coupled to the negative transmission line.

A method of driving a differential signal, the method comprising:

• providing a constant current at a first voltage;
• shifting the first voltage to a second voltage;
• and
• selectively steering the constant current at the second voltage to flow either from a positive differential node, through a terminating resistor, to a negative differential node, or from the negative differential node through the terminating resistor, to the positive differential node, according to a data signal to transmit the differential signal.