Analog Devices Inc./Maxim Integrated DS3253+

Overview

DS3253+ from Maxim Integrated (now Analog Devices) is a triple-channel line interface unit (LIU) for DS3/E3/STS-1 physical-layer interfacing, featuring independent receive/transmit paths per channel, on-chip jitter attenuation with 16–128-bit configurable FIFO depth, and clock adaptation from a single 19.44/38.88/77.76MHz or line-rate input. It supports B3ZS/HDB3 encoding/decoding and operates across industrial temperature range (–40°C to +85°C) in a 144-pin thermally enhanced CSBGA package.

For engineers reviewing the DS3253+ datasheet, DS3253+ pinout, DS3253+ application, or DS3253+ equivalent, key selection considerations include its triple-port DS3/E3/STS-1 compliance, hardware/parallel/SPI control interface flexibility, jitter transfer performance meeting Telcordia GR-253 and ITU G.823/G.824, and support for coaxial cable runs up to 380m (DS3), 440m (E3), or 360m (STS-1) without external equalization.

Technical Context

The DS3253+ implements three fully independent LIU channels, each integrating AGC + adaptive equalizer for loss compensation (0–15dB), clock and data recovery (CDR), dual-mode (binary/bipolar) framer interface, and programmable B3ZS/HDB3 encode/decode logic. Each channel supports local/remote loopbacks and per-channel power-down control.

Its on-chip clock adapter synthesizes all required line-rate clocks (DS3: 44.736MHz, E3: 34.368MHz, STS-1: 51.84MHz) from one master reference-eliminating need for discrete oscillators-and its crystal-less jitter attenuator meets ANSI T1.102, ITU G.823/G.824, and Telcordia GR-253 jitter transfer/output requirements when placed in either receive or transmit path.

Key Specifications

Pinout & Package

DS3253+ uses a 144-pin, 13mm × 13mm thermally enhanced CSP-BGA (TE-CSBGA) package with 0.8mm pitch and exposed thermal pad. Pin assignments vary by control interface mode (Hardware, Parallel, SPI); full mapping is defined in Figures 18-7 through 18-9 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS3153+, DS3253+ integrates clock adaptation and jitter attenuation - reducing external component count by ≥7 and improving jitter transfer margin by 3.2dB. Against TLK2201BRGPR, DS3253+ delivers triple-channel operation with embedded coding logic - enabling compact, low-risk deployment in multi-tributary access gear.

Availability

DS3253+ is available at Aetrix Electronics and suitable for SONET multiplexers, digital cross-connects, and DSLAM line cards requiring stable component supply, long-term lifecycle support, and guaranteed traceability for telecom infrastructure programs.

Supply support for DS3253+ 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) designs precision analog, mixed-signal, and high-speed communication ICs for industrial, telecom, and computing applications.

The DS3253+ belongs to Maxim's DS325x family of line interface units, engineered specifically for carrier-class DS3/E3/STS-1 physical layer interfacing in space-constrained, thermally demanding telecom infrastructure equipment.

FAQ

What telecommunication standards does the DS3253+ comply with?

The DS3253+ 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 certifications confirm its suitability for deployment in carrier-grade SONET/SDH, PDH, and digital cross-connect systems where strict jitter, signal integrity, and alarm handling requirements apply. DS3253+ meets all applicable requirements without external components.

How does the DS3253+ handle clock synthesis and jitter management?

The DS3253+ integrates an on-chip clock adapter that generates all required line-rate clocks-including DS3 (44.736MHz), E3 (34.368MHz), STS-1 (51.84MHz), and OC-3 (155.52MHz)-from a single input clock (e.g., 19.44MHz). Its crystal-less jitter attenuator, configurable for 16–128-bit FIFO depth, meets Telcordia GR-253 and ITU G.823/G.824 jitter transfer and output specifications whether placed in the receive or transmit path. DS3253+ achieves this with no external VCXO or PLL required.

What are the supported control interfaces for configuring the DS3253+?

The DS3253+ supports three mutually exclusive control modes: hardware mode (via dedicated config/status pins), 8-bit parallel interface (with Intel or Motorola bus timing), and SPI serial interface (up to 10 Mbps with programmable polarity/phase). Mode selection is determined by the HW pin state and bus strobe conditions. All modes provide full access to register-based configuration except hardware mode, which relies solely on pin strapping. DS3253+ retains key status pins (e.g., RLOSn, TTSn) active across all modes for real-time monitoring.

Does the DS3253+ support cable reach beyond standard DS3 distances?

Yes-the DS3253+ supports up to 380 meters of 75Ω coaxial cable in DS3 mode, 440 meters in E3 mode, and 360 meters in STS-1 mode, thanks to its integrated AGC and adaptive equalizer that compensates 0–15dB of cable loss. This exceeds the typical 225-meter DS3 limit defined in ANSI T1.102 and enables longer drop lengths in central office and remote terminal deployments without external repeaters. DS3253+ achieves this reach while maintaining full compliance with jitter and waveform template requirements.

Is JTAG boundary scan supported on the DS3253+?

Yes-the DS3253+ includes full IEEE 1149.1 JTAG test access port and boundary scan capability, supporting device identification, interconnect testing, and in-system programming of configuration registers. The JTAG interface operates independently of the primary control mode and is accessible via dedicated TCK, TMS, TDI, TDO, and TRST pins. This enables automated optical inspection (AOI) validation, production ICT, and post-deployment diagnostics without requiring host CPU intervention. DS3253+ implements all mandatory JTAG instructions and supports IDCODE and BYPASS registers per IEEE 1149.1.