12 LVPECL/24 CMOS Output Clock
Generator with Integrated 1.6 GHz VCO
Low phase noise, phase-locked loop (PLL)
On-chip VCO tunes from 1.4 GHz to 1.8 GHz
Supports external 0 V to 5 V VCO/VCXO to 2.4 GHz
1 differential or 2 single-ended reference inputs
Accepts CMOS, LVDS, or LVPECL references to 250 MHz
Accepts 16.67 MHz to 33.3 MHz crystal for reference input
Optional reference clock doubler
Reference monitoring capability
Auto and manual reference switchover/holdover modes,
with selectable revertive/nonrevertive switching
Glitch-free switchover between references
Automatic recover from holdover
Digital or analog lock detect, selectable
Optional zero delay operation
Twelve 1.6 GHz LVPECL outputs divided into 4 groups
Each group of 4 has a 1-to-32 divider with phase delay
Additive output jitter as low as 225 fS rms
Channel-to-channel skew grouped outputs <16 ps
Each LVPECL output can be configured as two CMOS
outputs (for fOUT ≤ 250 MHz)
Automatic synchronization of all outputs on power-up
Manual synchronization of outputs as needed
SPI- and I²C-compatible serial control port
Nonvolatile EEPROM stores configuration settings
Low jitter, low phase noise clock distribution
Clock generation and translation for SONET, 10Ge, 10G FC,
and other 10 Gbps protocols
Forward error correction (G.710)
Clocking high speed ADCs, DACs, DDSs, DDCs, DUCs, MxFEs
High performance wireless transceivers
ATE and high performance instrumentation
The AD9520-41 provides a multioutput clock distribution
function with subpicosecond jitter performance, along with an
on-chip PLL and VCO. The on-chip VCO tunes from 1.4 GHz to
1.8 GHz. An external 3.3 V/5 V VCO/VCXO of up to 2.4 GHz
can also be used.
FUNCTIONAL BLOCK DIAGRAM
The AD9520 serial interface supports both SPI and I2C® ports.
An in-package EEPROM can be programmed through the serial
interface and store user-defined register setting for power-up
and chip reset.
The AD9520 features 12 LVPECL outputs in four groups. Any
of the 1.6 GHz LVPECL outputs can be reconfigured as two
250 MHz CMOS outputs.
Each group of outputs has a divider that allows both the divide
ratio (from 1 to 32) and phase (coarse delay) to be set.
The AD9520 is available in a 64-lead LFCSP and can be operated
from a single 3.3 V supply. The external VCO can have an
operating voltage up to 5.5 V. A separate output driver power
supply can be from 2.375 V to 3.465 V.
The AD9520 is specified for operation over the standard industrial
range of −40°C to +85°C.
1 The AD9520 is used throughout this data sheet to refer to all the members of the AD9520 family. However, when AD9520-4 is used, it is referring to that specific
member of the AD9520 family.
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