GENERAL DESCRIPTION
The AD9553 is a phase-locked loop (PLL) based clock translator designed to address the needs of passive optical networks (PON) and base stations. The device employs an integer-N PLL to accommodate the applicable frequency translation requirements. The user supplies up to two single-ended input reference signals or one differential input reference signal via the REFA and REFB inputs. The device supports holdover applications by allowing the user to connect a 25 MHz crystal resonator to the XTAL input.

FEATURES
   Input frequencies from 8 kHz to 710 MHz
   Output frequencies up to 810 MHz
   Preset pin-programmable frequency translation ratios cover
      popular wireline and wireless frequency applications,
      including xDSL, T1/E1, BITS, SONET, and Ethernet.
   Arbitrary frequency translation ratios via SPI port
   On-chip VCO
   Accepts a crystal resonator for holdover applications
   Two single-ended (or one differential) reference input(s)
   Two output clocks (independently programmable as LVDS,
      LVPECL, or CMOS)
   SPI-compatible, 3-wire programming interface
   Single supply (3.3 V)
   Very low power: <450 mW (under most conditions)
   Small package size (5 mm × 5 mm)
   Exceeds Telcordia GR-253 Category II OC-48 jitter
      generation, transfer, and tolerance specifications

APPLICATIONS
   Cost effective replacement of high frequency VCXO, OCXO,
      and SAW resonators
   Extremely flexible frequency translation for SONET/SDH,
      Gb Ethernet, Fibre Channel, DRFI/DOCSIS, and
      PON/EPON/GPON
   Wireless infrastructure
   Test and measurement (including handheld devices)