General Description

The 78P2351R is Teridian’s second generation Line Interface Unit (LIU) for 155 Mbit/s electrical SONET/SDH interfaces (ES1, STM-1e). The device is a single chip solution that includes an integrated Clock Recovery Unit in the transmit path for simple, cost efficient NRZ to CMI conversion.

The device interfaces to 75Ω coaxial cable through wideband transformers and can handle over 12.7dB of cable loss.

With integrated CDR capabilities in the transmit path and a small 7x7mm QFN package, the 78P2351R is ideal for new STM-1e Small Form-factor Pluggable (SFP) transceiver modules.


  • G.703 compliant, adjustable cable driver for 155.52 Mbps CMI-coded coax transmission
  • Integrated adaptive CMI equalizer and CDR in receive path handles over 12.7dB of cable loss
  • Serial, LVPECL-compatible system interface with integrated CDR in transmit path for flexible NRZ to CMI conversion
  • Configurable via HW control pins or 4-wire serial port interface
  • Compliant with ANSI T1.105.03-1994; ITU-T G.813, G.825, G.958; and Telcordia GR-253-CORE for jitter performance
  • Provides G.783 compatible Loss of Signal (LOS) detection
  • Receive Monitor Mode handles up to 20dB of flat loss (at max 6dB cable loss)
  • Optional fixed backplane equalizer compensates for up to 1.5m of trace
  • Operates from a single 3.3V supply
  • Available in a small 7x7mm 56-pin QFN package
  • Industrial Temperature: -40ºC to +85°C