lvds rx
configured as a switched-polarity current generator. A differential load resistor at the receiver end provides current-tovoltage conversion and optimum line matching at the same time, Fig. (a). For operation in the gigabits-per-second range, an additional termination resistor is usually placed at the source end to suppress reflected waves caused by crosstalk or by imperfect termination, due to package parasitics and component tolerance, Fig. (b).
please refer to H.W. Johnson and M. Graham, High-Speed Digital Design, A Handbook of Black Magic.