Analog Devices Inc./Maxim Integrated DS2155LNC2+

Overview

DS2155LNC2+ from Maxim Integrated is a software-selectable T1/E1/J1 single-chip transceiver (SCT) integrating line interface unit (LIU), framer, dual HDLC controllers, and TDM backplane interface. It operates across -40°C to +85°C, supports 75Ω/120Ω media, delivers CMI coding, and features crystal-less jitter attenuation for telecom line cards and routers.

For engineers reviewing the DS2155LNC2+ datasheet, DS2155LNC2+ pinout, DS2155LNC2+ application, or DS2155LNC2+ equivalent, key selection criteria include software-selectable T1/E1/J1 mode, dual elastic-store slip buffers, programmable termination resistors, synthesized backplane clock outputs (2.048–16.384MHz), and JTAG boundary-scan test support.

Technical Context

The DS2155LNC2+ implements independent transmit and receive paths with full G.703-compliant waveform generation for E1 (75Ω coax, 120Ω twisted pair) and DSX-1/CSU line buildouts for T1 (-7.5dB, -15dB, -22.5dB). Its LIU includes jitter attenuator, short-circuit/open-circuit detection, and BPV error insertion.

It integrates dual HDLC controllers with FIFO-based packet handling, programmable BERT generator/detector, and fractional T1/E1 support. The TDM backplane interface connects asynchronously up to 16.384MHz using two-frame elastic-store buffers and supports interleaved PCM bus operation (IBO).

Key Specifications

Pinout & Package

DS2155LNC2+ is housed in a 100-pin LQFP (14mm × 14mm, 0.5mm pitch) package with exposed thermal pad. Pin functions are grouped into transmit/receive LIU, parallel control port (Intel/Motorola bus compatible), extended system information bus (ESIB), JTAG test access, and user output ports.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar T1/E1 transceiver applications.

Compared with DS2155LNC2+, DS2156LN+ offers improved jitter attenuation and expanded E1 diagnostics while maintaining full backward compatibility; MC2021A reduces integration but increases component count and limits multimode flexibility.

Availability

DS2155LNC2+ is available at Aetrix Electronics and suitable for telecom line cards, switches and routers, add-drop multiplexers, and network monitoring probes requiring stable component supply across industrial temperature ranges.

Supply support for DS2155LNC2+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.

The DS2155LNC2+ belongs to Maxim's legacy telecom transceiver product line, designed specifically for carrier-grade T1/E1/J1 line interface applications where software configurability, jitter resilience, and system-level integration reduce board complexity.

FAQ

What is the operating temperature range for DS2155LNC2+?

The DS2155LNC2+ is rated for industrial operation from -40°C to +85°C. This range is validated per Maxim's qualification standards and supports deployment in uncontrolled telecom central office and outdoor cabinet environments. The DS2155LNC2+ uses thermally enhanced 100-pin LQFP packaging with an exposed pad to maintain junction temperature within specification under full load.

Does DS2155LNC2+ support both T1 and E1 modes simultaneously?

No, DS2155LNC2+ operates in a single selected mode-T1, E1, or J1-at any given time, configured via software registers during initialization. While it cannot process both standards concurrently, its software-selectable architecture allows runtime reconfiguration, enabling flexible use across multi-region deployments without hardware changes. The DS2155LNC2+ maintains full feature parity across all three modes.

What clock frequencies does DS2155LNC2+ synthesize for the backplane interface?

The DS2155LNC2+ synthesizes four fixed backplane clock outputs: 16.384MHz, 8.192MHz, 4.096MHz, and 2.048MHz-all phase-locked to the recovered network clock. These frequencies align with standard TDM bus rates (e.g., 16.384MHz for 256-channel T1/E1 time slots) and are selected via register configuration. No external PLL or crystal is required due to the integrated crystal-less jitter attenuator.

How does DS2155LNC2+ handle line termination for different cable types?

The DS2155LNC2+ provides software-selectable termination resistors-75Ω, 100Ω, or 120Ω-configured independently for transmit and receive sides. This supports G.703-compliant operation on 75Ω coaxial and 120Ω twisted-pair cables in E1 mode, and DSX-1/CSU line buildouts in T1 mode. Termination selection is done via LIU control registers and requires no external components or solder-jumper changes.

Is DS2155LNC2+ pin-compatible with other devices in the DS2155 family?

Yes, all DS2155 variants-including DS2155LNC2+, DS2155LN+, DS2155L+, and DS2155G+-share identical 100-pin LQFP or CSBGA footprints and pin functions. The "C2" suffix in DS2155LNC2+ denotes a specific wafer lot and assembly revision, not a functional or mechanical deviation. Engineers may substitute across temperature grades or package types without layout modification.