The VSC8141 is a SONET/SDH compatible 3.3V multi-rate transceiver with integrated clock generator for use in SONET/SDH systems operating at OC-48, OC-24, OC-12, OC-3, or Gigabit Ethernet data rates. The internal clock generator uses a phase-locked loop (PLL) to multiply either a 77.76MHz or 155.52MHz reference clock for internal logic and output retiming. The 16-bit parallel LVPECL interface incorporates an on-board FIFO to address loop timing design issues. Facility and Equipment Loopbacks can be configured separately or simultaneously. The VSC8141 supports 3.3V operation with 2.3 Watts maximum power (1.8 Watts typical) and is packaged in a thermally-enhanced 128-pin PQFP or 208-pin TBGA package.