| 摘要 |
A hybrid output driver includes a voltage mode main driver having an adjustable differential output voltage swing, and a current mode emphasis driver. Differential output voltage swing is adjusted by controlling the resistance of a first adjustable resistor coupled to a first voltage supply terminal, and the resistance of a second adjustable resistor coupled to a second voltage supply terminal. Resistances of the first and second adjustable resistors are adjusted by modifying a number of resistors connected in parallel. A calibration process measures the actual resistance of a similar resistor, and uses this resistance measurement to determine the number of resistors to be connected in parallel to provide the desired resistance. The current mode emphasis driver sources/sinks currents to/from differential output terminals of the hybrid output driver in response to an emphasis signal. These currents are selected in view of the selected differential output voltage swing and selected emphasis level. |
