Patent ID: 7609097
Filing Date: 2009-10-27
Classification: H03K,H04L

Abstract:
1. A line driver circuit of an integrated circuit (IC), comprising: a first current source configured to operate in a triode region such that it has a first impedance value when the first current source is active; a first resistor connected in parallel with the first current source, the first resistor having a first resistance value; a second current source configured to operate in a triode region such that it has a second impedance value when the second current source is active; current switching circuitry coupled to at least one of the first and second current sources; a second resistor connected in parallel with the second current source, the second resistor having a second resistance value; and a source termination resistor connected across output terminals of the driver circuit, wherein the first and second resistance values and the source termination resistance value are set such that a combination of the first and second impedances, the first and second resistors and the source termination resistor provides the driver circuit with a desired output impedance, wherein the source termination resistance value (R