GENERAL DESCRIPTION

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.

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.

FEATURES

  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

  64-lead LFCSP

  Nonvolatile EEPROM stores configuration settings

  APPLICATIONS

  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

  Broadband infrastructures