Patent ID: 8743973

Claim:
A receiver circuit to receive signals from first and second pairs of transmission lines external to the receiver circuit, wherein the first pair of transmission lines and the second pair of transmission lines each have a common-mode impedance and a differential-mode impedance, the receiver circuit comprising: first and second interfaces, each comprising a first input node and a second input node, the first and second input nodes of a respective interface to receive respective ones of the signals from respective ones of the transmission lines; a resistor network comprising: first and second resistive elements, each connected between the first input node and the second input node of a respective one of the first and second interfaces, wherein the first and second respective resistive elements each have a resistance 2*R 0 ; and third and fourth resistive elements, each comprising: a respective pair of resistors connected in series between the first input node and second input node of a respective one of the first and second interfaces, and an intermediate node between the resistors, the intermediate node connected to an AC ground; wherein each resistor of the third and fourth respective resistive elements has a resistance R 1 ; a differential amplifier comprising a first input coupled to the first interface, a second input coupled to the second interface, and an output to provide a signal derived from common mode components of the signals received at the first and second input nodes of the first and second interfaces; and four resistors, each connecting a respective input node of the first and second interfaces to a common reference level, wherein the four resistors each have a resistance R 2 ; wherein: the resistances R 1 and R 2 have values such that a parallel combination of resistance R 1 and resistance R 2 is nominally equal to twice the common-mode impedance of the first and second respective pairs of transmission lines; and the resistances R 0 , R 1 , and R 2 have values such that a parallel combination of resistance R 0 , resistance R 1 , and resistance R 2 is nominally equal to one-half the differential-mode impedance of the first and second respective pairs of transmission lines.