A signal driver may include a variable termination resistor and a signal transmission line. The variable termination resistor may include one or more variable termination resistor units. Each of the one or more variable termination resistor units may include a switch connected to a first end node of the variable termination resistor; a T-coil connected to the switch; a first resistor connected to the first end node of the variable termination resistor and to the T-coil; and a second resistor connected to a second end node of the variable termination resistor and to the T-coil. The signal transmission line may be connected to the second end node of the variable termination resistor.