3.3V Communications Clock PLL

The MK2049-45A is a dual Phase-Locked Loop (PLL) device that can provide frequency synthesis and jitter attenuation. The first PLL is VCXO-based and uses a pullable crystal to track signal wander and attenuate input jitter. The second PLL is a translator for frequency multiplication. Basic configuration is determined by a Mode/Frequency Selection Table. Loop bandwidth and damping factor are programmable via external loop filter component selection. Buffer Mode accepts a 10MHz to 50MHz input and will provide a jitter attenuated output at 0.5 x ICLK, 1 x ICLK, or 2 x ICLK. In this mode, the MK2049-45A is ideal for filtering jitter from high-frequency clocks. In External Mode, ICLK accepts an 8kHz clock and will produce output frequencies from a table of common communications clock rates, CLK and CLK/2. This allows for the generation of clocks frequency-locked to an 8kHz backplane clock, simplifying clock synchronization in communications systems. The MK2049-45A can be dynamically switched between T1, E1, T3, and E3 outputs with the same 24.576MHz crystal. Renesas can customize these devices for many other different frequencies.