GENERAL DESCRIPTION

The XRT91L81 is a fully integrated SONET/SDH transceiver block for applications in SONET OC-48 allowing the use of Forward Error Correction (FEC) capability. The transceiver includes an on-chip Clock Multiplier Unit (CMU), which uses a high frequency Phase-Locked Loop (PLL) to generate the highspeed transmit serial clock from slower external clock references. It also provides Clock and Data Recovery (CDR) functions by synchronizing its on-chip Voltage Controlled Oscillator (VCO) to the incoming serial data stream.

FEATURES

? 2.488 / 2.666 Gbps Transceiver

? Single-chip fully integrated solution containing parallel-to-serial converter, clock multiplier unit (CMU), serial-to-parallel converter, limiting amplifier and clock data recovery (CDR) functions

? Host mode serial microprocessor interface simplifies monitor and control

? Provides support for dual fiber rings

? Integrated limiting amplifier accepts differential inputs down to 10mVp-p

? Separate reference and VCXO input ports support multiple de-jittering modes

? On-chip phase detector and charge pump for external VCXO based de-jittering PLL

? Targeted for SONET OC-48/SDH STM-16 Applications

? Selectable full duplex operation between standard rate of 2.488 Gbps or Forward Error Correction rate of 2.666 Gbps

? 4-bit LVDS data paths at 622/666 MHz complies with OIF SFI-4 Implimentation Agreement

? Internal FIFO decouples transmit input and output clocks

? Tx CMU and Rx CDR lock detect

? Provides Local, Remote and Split Loop-Back modes as well as Loop Timing mode

? Diagnostics features include various lock detect functions

? Meets Telcordia, ANSI and ITU-T jitter requirements

? Operates at 1.8V with 3.3V I/O

? 600mW Typical Power Dissipation

? Package: 12 x 12 mm 196-pin STBGA

APPLICATIONS

? SONET/SDH-based Transmission Systems

? Add/Drop Multiplexers

? Cross Connect Equipment

? ATM and Multi-Service Switches, Routers and Switch/Routers

? DSLAMS

? SONET/SDH Test Equipment

? DWDM Termination Equipment

? Optical Modules and Sub-Systems