78P2351-IGTR/F

Overview

The 78P2351-IGTR/F is a single-channel Line Interface Unit (LIU) designed for 155 Mbps OC-3/STM-1 and 140 Mbps E4 telecom interfaces. It integrates an adaptive CMI equalizer and clock recovery circuit in the receive path, supporting over 12.7dB of cable loss. The device features a flexible serial LVPECL or 4-bit parallel CMOS system interface with selectable master/slave timing modes. It operates from a single 3.3V supply and supports both 75Ω coaxial CMI transmission and direct fiber optic NRZ interfacing. The component is housed in a 100-pin JEDEC LQFP package.

Feature Summary

• Integrated adaptive equalizer and clock recovery unit handles significant cable loss in the receive path.
• Flexible system interface options including serial LVPECL and 4-bit parallel CMOS with configurable timing modes.
• Supports dual media connectivity via selectable CMI coding for coaxial cables or NRZ coding for optical transceivers.
• Configurable through hardware control pins or a 4-wire serial interface for mode selection and diagnostics.

Applications

• Central Office Interconnects
• DSLAMs
• Add Drop Multiplexers (ADMs)
• PDH/SDH test equipment
• Multi Service Switches

Procurement Notes

Verify component authenticity through authorized distributors or manufacturer channels. Confirm the specific suffix indicates tape-and-reel packaging if required by assembly processes. Check for end-of-life status as this model may be discontinued. Ensure compatibility with existing design specifications before procurement.

Selection Notes

Select this component for applications requiring a single-chip solution for OC-3/STM-1 or E4 line interfaces. Consider the integrated CDR and equalizer benefits for long cable runs. Evaluate interface requirements to determine if serial LVPECL or parallel CMOS modes suit the host framer. Verify power supply constraints align with the single 3.3V operation requirement.

Part Context

This part belongs to the 78P2351 series of Line Interface Units originally developed by Teridian Semiconductor Corporation, now under Analog Devices/Maxim Integrated. The series provides specialized interface solutions for high-speed telecom data transmission standards.

Replacement Considerations

Check for active equivalents within the same product family. Verify pinout and register compatibility if substituting with other LIU models. Confirm that alternative components support the same jitter tolerance and transfer functions specified by ANSI and ITU-T standards.

FAQ

How does the 78P2351 handle cable loss in the receive path?

The device includes an integrated adaptive CMI equalizer and clock recovery circuit capable of handling over 12.7dB of cable loss.

What interface options are available for connecting to the host system?

It offers a serial LVPECL-compatible interface and a 4-bit parallel CMOS interface, both supporting master and slave clock modes.

Can the device operate with both coaxial and fiber optic media?

Yes, it can interface to 75Ω coaxial cable using CMI coding or directly to a fiber optics transceiver module using NRZ coding.