DS26303LN-120+

Telecom Overview

The DS26303LN-120+ is an octal line interface unit (LIU) supporting E1, T1, and J1 short-haul transmission from a single 3.3V supply. It integrates eight independent channels with internal software-selectable termination, defaulting to 120Ω impedance for the -120 suffix. The device features a crystal-less jitter attenuator, selectable AMI or HDB3/B8ZS encoding, and dual-rail/single-rail modes. It supports hardware and serial interfaces, G.772 nonintrusive monitoring, and built-in BERT diagnostics. Operating in the -40°C to +85°C range, it is housed in a 144-pin eLQFP package.

Telecom Feature Summary

• Integrates eight independent E1/T1/J1 line interface units with internal software-selectable transmit and receive-side termination.
• Includes a crystal-less jitter attenuator and on-chip synthesizer generating clock rates from a single master clock input.
• Supports configurable single-rail and dual-rail modes with selectable AMI or HDB3/B8ZS line encoding and decoding.
• Provides comprehensive diagnostic capabilities including built-in BERT testers, digital/analog loss-of-signal detection, and AIS generation.

Telecom Applications

• T1 Digital Cross-Connects
• ATM and Frame Relay Equipment
• Wireless Base Stations
• E1/T1/J1 Multiplexer and Channel Banks

Telecom Procurement Notes

Verify the ordering suffix matches the required temperature grade (-LN indicates -40°C to +85°C) and impedance setting (-120 defaults to 120Ω). Confirm RoHS compliance status associated with the '+' designation. Ensure the 144-pin eLQFP package variant aligns with PCB layout specifications. Validate that the specific revision does not contain undocumented errata affecting system timing.

Telecom Selection Notes

Select this component when designing systems requiring multiple E1, T1, or J1 channels within a compact footprint. The integrated termination reduces external component count compared to discrete solutions. Consider the 120Ω default impedance for standard twisted-pair applications. Evaluate the single 3.3V supply requirement against available power rails. Verify host interface compatibility with Intel or Motorola parallel modes or 4-wire serial protocols.

Telecom Part Context

This part belongs to the DS26303 family of octal LIUs manufactured by Analog Devices/Maxim Integrated. It serves as a high-density solution for telecom infrastructure, consolidating eight channels into one package. The device replaces older multi-chip implementations, simplifying board design while maintaining compliance with ANSI T1.102 and ITU-T G.703 standards.

Telecom Replacement Considerations

Direct replacements include other DS26303 variants with different temperature ranges or impedance suffixes, such as DS26303L-120+. Cross-family substitution requires verifying pinout compatibility and register-level functional equivalence with competing octal LIUs.