The NB4L339 is a multi-function Clock generator featuring a 2:1 Clock multiplexer front end and simultaneously outputs a selection of four different divide ratios from its four divider blocks; 1/2/4/8. One divide block has a choice of 1 or 2. The output of each divider block is fanned-out to two identical differential LVPECL copies of the selected clock. All outputs provide standard LVPECL voltage levels when externally terminated with a 50-ohm resistor to VCC - 2 V.