Analog Devices Inc./Maxim Integrated DS3254A3+

Overview

DS3254A3+ from Maxim Integrated (now Analog Devices) is a quad-line interface unit (LIU) for DS3/E3/STS-1 physical-layer interfacing, featuring four independent receive/transmit paths, on-chip jitter attenuators with 16–128-bit provisionable FIFO depth, and a clock adapter synthesizing line-rate clocks from a single 19.44/38.88/77.76MHz or DS3/E3/STS-1 input. It supports B3ZS/HDB3 encoding/decoding and operates across -40°C to +85°C in telecom infrastructure.

For engineers reviewing the DS3254A3+ datasheet, DS3254A3+ pinout, DS3254A3+ application, or DS3254A3+ equivalent, key selection criteria include jitter attenuation path placement (RX/TX/disabled), control interface mode (parallel/SPI/hardware), cable reach (380m DS3, 440m E3, 360m STS-1 over 75Ω coax), and compliance with ANSI T1.102/T1.231, ITU G.703/G.823/G.824, and Telcordia GR-253-CORE.

Technical Context

The DS3254A3+ implements four fully independent LIU channels, each with AGC/equalizer supporting 0–15dB cable loss, dual-mode framer interface (binary/bipolar), and programmable PRBS generator/detector (2¹⁵−1 and 2²³−1). Its receiver includes analog/digital LOS detection per ANSI T1.231 and ITU G.775, while the transmitter provides DS3 AIS generation (ANSI T1.107) and E3 unframed all-ones output.

Jitter management uses an on-chip crystal-less attenuator meeting Telcordia GR-499-CORE and ITU G.823/G.824 transfer/output jitter requirements. The clock adapter accepts DS3 (44.736MHz), E3 (34.368MHz), STS-1 (51.84MHz), or standard frequencies (19.44/38.88/77.76MHz) and synthesizes all required line-rate clocks without external oscillators.

Key Specifications

Pinout & Package

DS3254A3+ is housed in a 144-pin thermally enhanced CSBGA (13mm × 13mm) package with exposed thermal pad. Pin assignments vary by control interface mode (hardware, parallel, or SPI); full pin mapping is defined in Figures 18-10 through 18-12 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar line interface unit applications.

Compared with DS3254N+, DS3254A3+ requires verification of temperature rating for industrial use; compared with DS3154+, DS3254A3+ integrates jitter attenuation and clock synthesis, reducing bill-of-materials and improving jitter compliance out-of-box.

Availability

DS3254A3+ is available at Aetrix Electronics and suitable for SONET/SDH multiplexers, digital cross-connect systems, and DSLAM line cards requiring stable component supply, long-term lifecycle support, and compliance with telecommunications standards including ANSI T1.x, ITU G.x, and Telcordia GR-253-CORE.

Supply support for DS3254A3+ 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, designs high-performance analog and mixed-signal ICs for communications, computing, and industrial applications.

The DS3254A3+ belongs to the DS325x family of line interface units engineered specifically for DS3/E3/STS-1 physical-layer interfacing in carrier-grade telecom infrastructure, emphasizing jitter control, multi-standard compliance, and minimal external component count.

FAQ

What telecommunication standards does the DS3254A3+ comply with?

The DS3254A3+ complies with ANSI T1.102 (DS3/E3 electrical interfaces), T1.231 (layer-1 performance monitoring), ITU G.703 (physical/electrical characteristics), G.823/G.824 (jitter control), and Telcordia GR-253-CORE (SONET transport). These ensure interoperability in carrier networks and adherence to global line interface requirements.

How many independent line interface channels does the DS3254A3+ provide?

The DS3254A3+ provides four independent line interface channels, each with dedicated receive and transmit paths, AGC/equalizer, clock and data recovery, jitter attenuator, and B3ZS/HDB3 encode/decode capability-enabling simultaneous DS3, E3, and STS-1 operation per port.

What clock frequencies can the DS3254A3+ accept for its on-chip clock adapter?

The DS3254A3+ clock adapter accepts a single input clock at DS3 (44.736MHz), E3 (34.368MHz), STS-1 (51.84MHz), or standard system frequencies: 19.44MHz, 38.88MHz, or 77.76MHz. From this, it synthesizes all required line-rate clocks without external oscillators.

Does the DS3254A3+ support both hardware and processor-controlled configuration?

Yes, the DS3254A3+ supports three configuration modes: hardware mode (via dedicated pins), 8-bit parallel CPU interface (Intel/Motorola timing), and SPI serial interface (up to 10Mbit/s). Mode selection is controlled by the HW pin and bus signal states per Section 5 of the datasheet.

What is the maximum coaxial cable reach supported by the DS3254A3+ receiver?

The DS3254A3+ receiver supports up to 380 meters over 75Ω coaxial cable for DS3, 440 meters for E3, and 360 meters for STS-1-enabled by its integrated AGC and adaptive equalizer that compensates for 0–15dB of cable loss per channel.