The MAX3872 is a compact, multirate clock and data
recovery with limiting amplifier for OC-3, OC-12, OC-24,
OC-48, OC-48 with FEC SONET/SDH and Gigabit
Ethernet (1.25Gbps/2.5Gbps) applications. Without using
an external reference clock, the fully integrated phase-locked
loop (PLL) recovers a synchronous clock signal
from the serial NRZ data input. The input data is then
retimed by the recovered clock, providing a clean data
output. An additional serial input (SLBI±) is available for
system loopback diagnostic testing. Alternatively, this
input can be connected to a reference clock to maintain a
valid clock output in the absence of data transitions. The
device also includes a loss-of-lock (active-low LOL) output.
The MAX3872 contains a vertical threshold control to
compensate for optical noise due to EDFAs in DWDM
transmission systems. The recovered data and clock
outputs are CML with on-chip 50Ω back termination on
each line. Its jitter performance exceeds all
SONET/SDH specifications.
The MAX3872 operates from a single +3.3V supply and
typically consumes 580mW. It is available in a 5mm x
5mm 32-pin thin QFN with exposed-pad package and
operates over a -40°C to +85°C temperature range.