Analog Devices Inc./Maxim Integrated DS2155GNC2+T&R

Overview

DS2155GNC2+T&R 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 supports long-haul and short-haul operation, delivers 75Ω/120Ω programmable termination, and provides crystal-less jitter attenuation for telecom line cards. Used in carrier-grade add-drop multiplexers and edge routers requiring precise clock/data recovery.

For engineers reviewing the DS2155GNC2+T&R datasheet, DS2155GNC2+T&R pinout, DS2155GNC2+T&R application, or DS2155GNC2+T&R equivalent, key selection criteria include T1/E1/J1 protocol flexibility, dual elastic-store slip buffers for asynchronous backplanes up to 16.384MHz, internal BERT generator/detector, CMI coding support, and software-selectable termination resistors for metallic/longitudinal protection schemes.

Technical Context

The DS2155GNC2+T&R implements fully independent transmit and receive paths with separate LIU sections: transmit generates G.703-compliant waveshapes for 75Ω coax and 120Ω twisted-pair E1, plus DSX-1/CSU line buildouts (-7.5dB, -15dB, -22.5dB) for T1. Receive recovers clock and data with jitter tolerance per ITU-T G.823/G.824 and ETSI EN 300 233.

Its dual HDLC controllers support simultaneous framing and signaling on T1 (D4/ESF) and E1 (PCM-30/ISDN-PRI) channels, while the TDM backplane interface operates at 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz - all synthesized from recovered network clock with fractional-N PLL.

Key Specifications

Pinout & Package

DS2155GNC2+T&R is housed in a 100-ball CSBGA package (5.0mm × 5.0mm, 0.5mm pitch), RoHS-compliant and lead-free. Pin configuration follows Maxim's 10mm CSBGA layout (documented in DS2155 datasheet Section 4.10).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2155GNC2+T&R, DS2156LN+ offers drop-in upgrade path with better jitter specs and extended temp rating, while MC2155A trades feature depth for lower cost and simpler integration - making it viable only in constrained, single-protocol systems.

Availability

DS2155GNC2+T&R is available at Aetrix Electronics and suitable for carrier-grade line cards, telecom edge routers, add-drop multiplexers, and enterprise PRI gateways requiring stable component supply and long-term lifecycle support.

Supply support for DS2155GNC2+T&R 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 semiconductor company specializing in high-performance analog, mixed-signal, and RF ICs for communications, computing, and industrial markets.

The DS2155GNC2+T&R belongs to Maxim's telecom transceiver product line, designed specifically for carrier-class TDM infrastructure requiring protocol flexibility, jitter resilience, and integration density in compact form factors.

FAQ

What protocols does the DS2155GNC2+T&R support?

The DS2155GNC2+T&R supports T1 (DS1, D4, ESF), E1 (PCM-30, ISDN-PRI), and J1 protocols in software-selectable mode. It handles framing, line coding (AMI/B8ZS for T1, HDB3 for E1), and signaling per ITU-T G.704, G.706, and ANSI T1.403 standards. Each protocol mode is configured via internal registers - no hardware changes required. The DS2155GNC2+T&R does not support T3, STM-1, or packet-based interfaces like Ethernet or SONET.

Does DS2155GNC2+T&R require an external crystal?

No, the DS2155GNC2+T&R features a crystal-less jitter attenuator that locks to the incoming network clock, eliminating the need for an external crystal or VCXO. This reduces bill-of-materials cost and board space while maintaining compliance with ITU-T G.823 jitter transfer and tolerance masks. An optional crystal can be connected for auxiliary clocking, but it is not required for basic operation. The DS2155GNC2+T&R derives all internal clocks-including backplane outputs-from the recovered network reference.

What is the package type and RoHS status of DS2155GNC2+T&R?

The DS2155GNC2+T&R uses a 100-ball CSBGA package measuring 5.0mm × 5.0mm with 0.5mm ball pitch. It is lead-free and RoHS-compliant, indicated by the "+" suffix in the part number. The package is qualified for industrial temperature range (-40°C to +85°C) and supports reflow soldering per JEDEC J-STD-020. Thermal resistance (θ_JA) is 35°C/W, and the device meets moisture sensitivity level 3 (MSL-3) per J-STD-020.

How does DS2155GNC2+T&R handle clock synchronization across domains?

The DS2155GNC2+T&R synchronizes its internal operations to the recovered network clock using a digital phase-locked loop (DPLL) within the jitter attenuator. It synthesizes stable backplane clock outputs (16.384MHz, 8.192MHz, etc.) phase-aligned to the network reference. Dual elastic-store slip buffers decouple the line-side and backplane clock domains, absorbing frequency differences up to ±100 ppm without data loss. This ensures deterministic latency and slip-free TDM transport in DS2155GNC2+T&R-based systems.

Can DS2155GNC2+T&R operate in both T1 and E1 modes simultaneously?

No, the DS2155GNC2+T&R operates in one protocol mode at a time - T1, E1, or J1 - selected during initialization via software configuration. While it integrates dual HDLC controllers and independent transmit/receive paths, the framer, LIU, and timing resources are shared and configured for a single standard per power-on cycle. Simultaneous T1+E1 operation would require two DS2155GNC2+T&R devices or a multi-port solution like the DS2175. Mode switching requires full register reinitialization.