Patent ID: 7099218

Claim:
A differential current evaluation circuit for connecting to a data line pair having a first signal line and a second signal line, the differential current evaluation circuit comprising: a differential amplifier having a first output, a second output, a first input functioning as a first input of the differential current evaluation circuit and electrically connected to the first signal line of the data line pair, and a second input functioning as a second input of the differential current evaluation circuit and electrically connected to the second signal line of the data line pair; and a circuit for setting an input resistance of the differential current evaluation circuit, said circuit electrically connected to said first and second outputs and said first and second inputs of said differential amplifier and to the first and second signal lines of the data line pair, said circuit having two transistors of a first conductivity type, said two transistors including a first transistor electrically connected to said first output, said first input, and to the first signal line, and a second transistor electrically connected to said second output, said second input, and the second signal line, said first transistor having a gate terminal, a first terminal and a second terminal, said first transistor being electrically connected to said first output of said differential amplifier by said gate terminal, to the first signal line of the data line pair by said first terminal and to a ground potential by said second terminal, and said second transistor having a gate terminal, a first terminal and a second terminal, said second transistor being electrically connected to said second output of said differential amplifier by said gate terminal, to the second signal line of the data line pair by said first terminal and to the ground potential by said second terminal.