Analog Devices Inc./Maxim Integrated DS21352LN

Overview

DS21352LN from Maxim Integrated is a 3.3V T1 single-chip transceiver supporting DS1/ISDN-PRI/J1 line interfaces, featuring crystal-less jitter attenuation (32- or 128-bit selectable), dual elastic store slip buffers for asynchronous backplanes up to 8.192 MHz, HDLC controller with 64-byte buffers configurable for FDL or DS0 operation, and full ANSI T1.403-1995 / ITU G.703–G.823 compliance for long- and short-haul LIU applications in telecom access equipment.

For engineers reviewing the DS21352LN datasheet, DS21352LN pinout, DS21352LN application, or DS21352LN equivalent, key selection criteria include T1 framer alarm detection (RLOS, RRA, RAIS, RCL), programmable in-band loop code generation (1–8 bits), IEEE 1149.1 JTAG boundary scan support, 100-pin LQFP package, and -40°C to +85°C industrial temperature rating.

Technical Context

The DS21352LN integrates independent transmit and receive data paths with dedicated elastic stores, each supporting 1.544 MHz or 2.048 MHz backplane clocks up to 8.192 MHz bursty operation. Its framer detects D4 (SLC-96) and ESF multiframe boundaries while extracting/inserting robbed-bit signaling and FDL data.

Line interface functionality includes automatic clock/data recovery from 0–6000 ft T1 lines, selectable DSX-1 or CSU line build-outs (-7.5 dB, -15 dB, -22.5 dB), and transformer-coupled analog I/O (TTIP/TRING, RTIP/RRING) with receive sensitivity from 0 dB to -36 dB.

Key Specifications

Pinout & Package

DS21352LN is housed in a 100-pin LQFP package (14 mm × 14 mm), with separate analog receive/transmit supply domains (RVDD/RVSS, TVDD/TVSS), digital core supply (DVDD/DVSS), and dedicated JTAG (JTMS/JTCLK/JTRST/JTDI/JTDO) and parallel control port pins (D0–D7, A0–A6, RD*, WR*, CS*, BTS, MUX, ALE).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS21552LN, DS21352LN enables lower-power 3.3V operation and eliminates level-shifting overhead; compared with DS21354LN, it offers cost-optimized T1 functionality without interleaving complexity-ideal for single-line-card deployments.

Availability

DS21352LN is available at Aetrix Electronics and suitable for telecom access equipment, T1 line cards, and ISDN PRI gateways requiring stable component supply, extended temperature operation, and long-term lifecycle assurance.

Supply support for DS21352LN 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 solutions for communications, industrial, and computing markets.

The DS21352LN belongs to Maxim's SCT (Single-Chip Transceiver) product line, designed specifically for integrated T1/E1 line interface applications in carrier-grade access equipment and enterprise telecom infrastructure.

FAQ

What is the operating temperature range of the DS21352LN?

The DS21352LN is rated for industrial operation from -40°C to +85°C. This specification ensures reliable performance in uncontrolled environments such as roadside cabinets, central office shelves, and outdoor DSLAM enclosures where ambient temperatures exceed commercial-grade limits. The DS21352LN maintains full electrical compliance-including jitter attenuation accuracy, line build-out stability, and alarm threshold consistency-across this entire range.

Does the DS21352LN require an external crystal?

No, the DS21352LN features a crystal-less jitter attenuator that synthesizes stable timing references internally. It derives its 8.192 MHz output clock directly from the recovered RCLK signal, eliminating the need for an external quartz crystal or oscillator. This reduces bill-of-materials cost, board space, and potential failure points associated with crystal aging or thermal drift-while still meeting ITU G.823 jitter transfer and tolerance requirements.

How does the DS21352LN handle T1 line alarms like RLOS and RRA?

The DS21352LN detects RLOS (Receive Loss of Signal), RRA (Receive Red Alarm), RAIS (Receive Alarm Indication Signal), and RCL (Receive Carrier Loss) in hardware and asserts them as status bits in internal registers. Each alarm also triggers the INT* pin to generate an interrupt, enabling immediate host processor response. Alarm thresholds-including RLOS sensitivity (0 dB to -36 dB) and RRA detection window-are fully compliant with ANSI T1.403-1995 and can be configured via the parallel control port without firmware overhead.

Can the DS21352LN interface with both 1.544 MHz and 2.048 MHz backplane clocks?

Yes, the DS21352LN supports both 1.544 MHz (T1) and 2.048 MHz (E1) backplane clocks on its RSYSCLK and TSYSCLK inputs. Its dual elastic store architecture allows independent clock domain handling-enabling simultaneous connection to T1 and E1 subsystems within the same chassis. The device accepts bursty clock inputs up to 8.192 MHz, accommodating time-division multiplexed backplane protocols without external clock conditioning.

Is the DS21352LN pin-compatible with other devices in the SCT family?

Yes, the DS21352LN is pin-compatible with DS2152/DS2154/DS21354/DS21554 single-chip transceivers in the same 100-pin LQFP package. This allows drop-in replacement during design refreshes or migration from legacy parts-preserving PCB layout, routing, and mechanical footprint. However, register mapping and certain advanced features (e.g., interleaved PCM bus in DS21354) differ and require firmware validation before substitution.