NB6L611 2.5V / 3.3V 1:2 Differential LVPECL Clock.
NB6L611 - Differential LVPECL Clock / Data Fanout Buffer
NB6L611 2.5V / 3.3V 1:2 Differential LVPECL Clock / Data Fanout Buffer Multi−Level Inputs with Internal Termination http://onsemi.com Description .