Patent ID: 6522179
Filing Date: 2003-02-18
Classification: H03F,H04L

Abstract:
A differential line driver circuit for driving a line signal output via a signal line, said circuit comprising:a first input terminal and a second input terminal for the application of an input signal, a fully differential operational amplifier having an inverting signal input connected to the first input terminal, a non-inverting signal input connected to the second input terminal, a first signal output for providing an amplified output signal in phase with the input signal, and a second signal output for providing an amplified output signal in phase opposition with the input signal, gain adjusting impedances for adjusting the gain of the differential line driver circuit, the gain adjusting impedances being connected between an input terminal of the line driver circuit and a signal input of the operational amplifier, a first feedback impedance connected between the inverting signal input of the operational amplifier and the first signal output of the operational amplifier, a second feedback impedance connected between the non-inverting signal input of the operational amplifier and the second signal output of the operational amplifier, a first matching impedance connected between the first signal output of the operational amplifier and a first output terminal of the line driver circuit, and a second matching impedance connected between the second signal output of the operational amplifier and a second output terminal of the line driver circuit, a first positive-feedback impedance connected between the first output terminal of the line driver circuit and the non-inverting signal input of the operational amplifier, and a second positive-feedback impedance, connected between the second output terminal of the line driver circuit and the inverting input of the operational amplifier, the output impedance of the line driver circuit being matched to the impedance of the line.