Analog Devices Inc./Maxim Integrated DS3252+

Overview

DS3252+ from Maxim Integrated (now Analog Devices) is a dual-channel Line Interface Unit (LIU) for DS3/E3/STS-1 physical-layer interfacing, featuring independent receive/transmit paths per channel, on-chip jitter attenuators with 16–128-bit provisionable FIFO depth, and a clock adapter synthesizing line-rate clocks (DS3: 44.736MHz, E3: 34.368MHz, STS-1: 51.84MHz) from a single input (e.g., 19.44MHz). It supports B3ZS/HDB3 encoding/decoding and operates across -40°C to +85°C in telecom infrastructure.

For engineers reviewing the DS3252+ datasheet, DS3252+ pinout, DS3252+ application, or DS3252+ equivalent, key selection considerations include its dual-port DS3/E3/STS-1 compliance, hardware/parallel/SPI control interface flexibility, jitter attenuation placement options (RX/TX path or disabled), and drop-in compatibility with legacy DS3152 LIUs in carrier-grade multiplexers and cross-connect systems.

Technical Context

The DS3252+ implements two fully independent LIU channels, each integrating AGC + adaptive equalizer for up to 15dB cable loss compensation, CDR with digital/analog LOS detection per ANSI T1.231 and ITU G.775, and programmable B3ZS/HDB3 encode/decode logic. Its jitter attenuator uses crystal-less architecture meeting Telcordia GR-253 and ITU G.823/G.824 requirements.

Each channel supports tri-state RCLK/TCLK outputs and TXP/TXN/RXP/RXN differential I/O compliant with 75Ω coaxial interface standards (ANSI T1.404, ITU G.703), with configurable framer interface polarity and gapped-clock operation up to 51.84MHz. The on-chip clock adapter eliminates external oscillators by deriving all line-rate clocks from one master source.

Key Specifications

Pinout & Package

DS3252+ is housed in a 144-pin, 13mm × 13mm thermally enhanced CSP-BGA (TE-CSBGA) package with exposed thermal pad, optimized for high-density telecom PCB layouts and thermal dissipation in fanless chassis.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS3152+, DS3252+ integrates clock synthesis and jitter attenuation, eliminating two external ICs and associated layout complexity; versus MAX3675, DS3252+ delivers dual-channel density, STS-1 support, and full Telcordia-compliant jitter performance required in central office deployments.

Availability

DS3252+ is available at Aetrix Electronics and suitable for digital cross-connect systems, SONET/SDH multiplexers, and DSLAM backhaul applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for carrier-grade production.

Supply support for DS3252+ 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 (acquired by Analog Devices in 2021) is a fabless semiconductor company specializing in high-performance analog, mixed-signal, and RF solutions for communications, computing, and industrial markets.

The DS3252+ belongs to Maxim's DS325x LIU product line, designed specifically for carrier-class TDM infrastructure requiring multi-standard (DS3/E3/STS-1) physical layer interfacing with integrated jitter management and flexible control architecture.

FAQ

What telecommunication standards does the DS3252+ comply with?

The DS3252+ complies with ANSI T1.102, T1.107, T1.231, and T1.404; ITU-T G.703, G.751, G.775, G.823, and G.824; ETSI ETS 300 686/687/EN 300 689; and Telcordia GR-253-CORE and GR-499-CORE. These cover DS3/E3/STS-1 electrical interface, framing, jitter, and alarm signaling requirements-ensuring interoperability in global carrier networks. DS3252+ meets all applicable specifications without external components.

Does the DS3252+ support both B3ZS and HDB3 line coding?

Yes, the DS3252+ supports optional B3ZS encoding/decoding for DS3 and HDB3 encoding/decoding for E3 within each channel. This is configurable per LIU port via control registers or hardware pins, enabling seamless interoperation with North American (B3ZS) and European/Asian (HDB3) TDM infrastructure. DS3252+ also provides line-code violation counters and status flags for real-time monitoring.

Can the jitter attenuator in the DS3252+ be used in both receive and transmit paths simultaneously?

No-the DS3252+ jitter attenuator is configurable per channel to reside exclusively in either the receive path, the transmit path, or be disabled; it cannot operate in both paths concurrently. This design allows precise placement where jitter cleanup is most critical-for example, attenuating incoming jitter before framing (RX path) or cleaning synthesized transmit clocks (TX path). DS3252+ provides overflow/underflow status bits for FIFO health monitoring.

What clock frequencies can the DS3252+ clock adapter accept as input?

The DS3252+ clock adapter accepts a single master clock input at DS3 (44.736MHz), E3 (34.368MHz), STS-1 (51.84MHz), or common system frequencies: 19.44MHz, 38.88MHz, or 77.76MHz. From any of these inputs, it synthesizes all required line-rate clocks internally-eliminating need for multiple oscillators. DS3252+ also optionally outputs synthesized clocks for adjacent framers or mappers, reducing system-level timing complexity.

Is the DS3252+ pin-compatible with earlier Maxim LIUs like the DS3152?

Yes, the DS3252+ is a documented drop-in replacement for the DS3152, sharing identical pinout, package (144-pin TE-CSBGA), and footprint. However, DS3252+ adds functionality-including integrated clock adapter, jitter attenuator, and enhanced diagnostics-without requiring PCB changes. Legacy DS3152 designs can be upgraded to DS3252+ to improve jitter performance and reduce bill-of-materials count.