
1.25 Gbps Clock and Data Recovery IC
Data Sheet
Rev. B
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FEATURES
Locks to 1.25 Gbps NRZ serial data input
Patented clock recovery architecture
No reference clock required
Loss-of-lock indicator
I2C interface to access optional features
Single-supply operation: 3.3 V
Low power: 390 mW typical
5 mm × 5 mm 32-lead LFCSP, Pb free
APPLICATIONS
GbE line card
GENERAL DESCRIPTION
The ADN2805 provides the receiver functions of quantization
and clock and data recovery for 1.25 Gbps. The ADN2805
automatically locks to all data rates without the need for an
external reference clock or programming. All SONET jitter
requirements are met, including jitter transfer, jitter generation,
and jitter tolerance.
All specifications are specified for 40°C to +85°C ambient
temperature, unless otherwise noted. The ADN2805 is available
in a compact 5 mm × 5 mm 32-lead LFCSP.
FUNCTIONAL BLOCK DIAGRAM
2
LOL
DATAOUTP/
DATAOUTN
ADN2805
CLKOUTP/
CLKOUTN
2
VCC
VEE
CF1
CF2
PIN
NIN
VREF
BUFFER
VCO
PHASE
SHIFTER
PHASE
DETECT
FREQUENCY
DETECT
DATA
RE-TIMING
LOOP
FILTER
LOOP
FILTER
REFCLKP/REFCLKN
(OPTIONAL)
07
12
1-
0
01
Figure 1.