78P2351R-IM/F

Overview

The 78P2351R is a single-chip Line Interface Unit (LIU) designed for 155.52 Mbit/s electrical SDH interfaces (STM1e). It performs NRZ to CMI conversion with integrated Clock & Data Recovery in both transmit and receive paths. The device interfaces to 75 Ω coaxial cable via wideband transformers, handling over 12.7 dB of cable loss. It operates from a single 3.3V supply and supports reference clock frequencies of 19.44 MHz, 77.76 MHz, or 155.52 MHz. The component is housed in a 7x7mm 56-pin QFN package and functions within an industrial temperature range of -40°C to +85°C.

Feature Summary

• Integrated adaptive equalizer and clock recovery in the receive path to compensate for significant cable attenuation.
• LVPECL-compatible system interface with built-in clock recovery for flexible NRZ to CMI conversion.
• Configurable operation through hardware control pins or a 4-wire serial port interface.
• Supports multiple loopback modes including local, remote analog, and full digital loopback.

Applications

• STM1e Small Form-factor Pluggable (SFP) transceiver modules
• SDH/ATM Line Cards
• Add Drop Multiplexers (ADMs)
• PDH/SDH Test Equipment

Procurement Notes

Verify the manufacturer origin, as the datasheet indicates Teridian Semiconductor Corporation. Confirm the specific ordering suffix matches the required package and temperature grade. Ensure the source document corresponds to Rev 2.1 dated August 2006 for accurate parameter validation.

Selection Notes

Select this component for STM1e applications requiring direct coaxial connection without external synchronous clocks. Verify that the system reference clock frequency aligns with the CKSL pin configuration options. Ensure the PCB layout accommodates the 56-pin QFN package and provides adequate thermal dissipation for the specified operating conditions.

Part Context

This device belongs to the second generation of Line Interface Units for 155 Mbit/s electrical SDH interfaces. It replaces discrete solutions by integrating CMI encoding, decoding, and clock recovery into a single chip, reducing board space and complexity for STM1e compliant systems.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.