Patent ID: 7471110

Claim:
A circuit device comprising: a first input responsive to a first transmission line to receive a first signal; a second input responsive to a second transmission line to receive a second signal; a first current comparator coupled to the first input to compare the first signal to a first reference current and to produce a first differential voltage at a first output node; a second current comparator coupled to the second input to compare the second signal to a second reference current and to produce a second differential voltage at a second output node; and a voltage comparator including a first input coupled to the first output node and a second input coupled to the second output node, the voltage comparator to sense a differential voltage between the first output node and the second output node and to provide an output voltage related to the first signal and the second signal, wherein the first current comparator comprises: a first transistor comprising: a first terminal coupled to the first input; a first control terminal coupled to the first terminal: a second terminal coupled to an electrical ground; and a second transistor comprising: a third terminal coupled to receive the first reference current; a second control terminal coupled to the first terminal of the first transistor; and a fourth terminal coupled to the electrical ground; wherein the first output node is coupled to the third terminal.