NB4L339 Overview
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. The differential Clock inputs incorporate internal 50−W termination resistors and will accept LVPECL, CML or LVDS logic levels. The mon Output Enable pin (EN) is synchronous so that the internal dividers will only be enabled/disabled when the internal clock is in the LOW state. This avoids any chance of generating a runt clock p