OC-48/OC-48 FEC Clock and
Data Recovery
Data Sheet
ADN2811
Rev. C Document Feedback
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FEATURES
Meets SONET requirements for jitter transfer/generation/
tolerance
Quantizer sensitivity: 4 mV typical
Adjustable slice level: ±100 mV
1.9 GHz minimum bandwidth
Patented clock recovery architecture
Loss of signal detect range: 3 mV to 15 mV
Single reference clock frequency for both native SONET and
15/14 (7%) wrapper rate
Choice of 19.44 MHz, 38.88 MHz, 77.76 MHz, or 155.52 MHz
REFCLK
LVPECL/LVDS/LVCMOS/LVTTL compatible inputs
(LVPECL/LVDS only at 155.52 MHz)
19.44 MHz on-chip oscillator to be used with external crystal
Loss of lock indicator
Loopback mode for high speed test data
Output squelch and bypass features
Single-supply operation: 3.3 V
Low power: 540 mW typical
7 mm × 7 mm, 48-lead LFCSP
APPLICATIONS
SONET OC-48, SDH STM-16, and 15/14 FEC
WDM transponders
Regenerators/repeaters
Test equipment
Backplane applications
PRODUCT DESCRIPTION
The ADN2811 provides the receiver functions of quantization,
signal level detect, and clock and data recovery at OC-48 and
OC-48 FEC rates. All SONET jitter requirements are met,
including jitter transfer, jitter generation, and jitter tolerance.
All specifications are quoted for −40°C to +85°C ambient
temperature, unless otherwise noted.
The device is intended for WDM system applications and can
be used with either an external reference clock or an on-chip
oscillator with external crystal. Both the 2.48 Gbps and 2.66 Gbps
digital wrapper rates are supported by the ADN2811, without
any change of reference clock.
This device, together with a PIN diode and a TIA preamplifier,
can implement a highly integrated, low cost, low power, fiber
optic receiver.
The receiver front end signal detect circuit indicates when the
input signal level has fallen below a user-adjustable threshold.
The signal detect circuit has hysteresis to prevent chatter at the
output.
The ADN2811 is available in a compact, 7 mm × 7 mm, 48-lead
chip scale package.
FUNCTIONAL BLOCK DIAGRAM
LEVEL
DETECT
DA TA
RETIMING
FRACTIONAL
DIVIDER
FREQUENCY
LOCK
DETECTOR
LOOP
FILTER
PHASE
SHIFTER
PHASE
DET.
VCO
XTAL
OSC
LOOP
FILTER
QUANTIZER
/n
ADN2811
SLICEP/N VCC VEE
CF1 CF2
LOL
REFSEL[0..1]
REFCLKP/N
XO1
XO2
REFSEL
RATECLKOUTP/NDATAOUTP/NSDOUT
THRADJ
VREF
NIN
PIN
2
2
22
2
03019-B-001
Figure 1.
