The NB6L56 is a high performance Dual 2-to-1 Differential Clock or Data multiplexer. The Multi-Level differential inputs incorporate internal 50 Ohms termination resistors that are accessed through the VT pin. This feature allows the NB6L56 to accept various Differential logic level standards, such as LVPECL, CML or LVDS. Outputs are 800 mV LVPECL signals.