622 Mbps Clock and Data Recovery IC
with Integrated Limiting Amplifier
ADN2804
FEATURES
Exceeds SONET requirements for jitter transfer/
generation/tolerance
Quantizer sensitivity: 3.3 mV typical
Adjustable slice level: ±95 mV
Patented clock recovery architecture
Loss-of-signal (LOS) detect range: 2.6 mV to 18.4 mV
Independent slice level adjust and LOS detector
No reference clock required
Loss-of-lock indicator
I
2
C® interface to access optional features
Single-supply operation: 3.3 V
Low power: 423 mW typical
5 mm × 5 mm, 32-lead LFCSP, Pb free
GENERAL DESCRIPTION
The ADN2804 provides the receiver functions of quantization,
signal level detect, clock and data recovery, and data retiming
for 622 Mbps NRZ data. The ADN2804 automatically locks to
622 Mbps data without the need for an external reference clock
or programming. In the absence of input data, the output clock
drifts no more than ±5%. 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.
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’s front-end loss-of-signal (LOS) detector circuit
indicates when the input signal level falls below a user-adjustable
threshold. The LOS detect circuit has hysteresis to prevent chatter
at the output.
The ADN2804 is available in a compact 5 mm × 5 mm,
32-lead LFCSP.
APPLICATIONS
BPON ONT
SONET OC-12
WDM transponders
Regenerators/repeaters
Test equipment
Broadband cross-connects and routers
FUNCTIONAL BLOCK DIAGRAM
REFCLKP/REFCLKN
(OPTIONAL)
LOL
CF1
CF2
VCC
VEE
SLICEP/SLICEN
PIN
NIN
2
FREQUENCY
DETECT
LOOP
FILTER
QUANTIZER
PHASE
SHIFTER
PHASE
DETECT
LOOP
FILTER
VCO
VREF
LOS
DETECT
DATA
RE-TIMING
2
2
THRADJ
LOS
DATAOUTP/
DATAOUTN
CLKOUTP/
CLKOUTN
ADN2804
05801-001
Figure 1.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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©2006 Analog Devices, Inc. All rights reserved.
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