Analog Devices Inc./Maxim Integrated DS21352L+

Overview

DS21352L+ from Maxim Integrated is a 3.3V T1 single-chip transceiver supporting DS1/ISDN-PRI/J1 line interface, long/short-haul LIU operation, crystal-less jitter attenuation (32- or 128-bit selectable), and HDLC controller with 64-byte buffers configurable for FDL or DS0 mode - deployed in telecom access equipment for T1 line termination.

For engineers reviewing the DS21352L+ datasheet, DS21352L+ pinout, DS21352L+ application, or DS21352L+ equivalent, this page delivers verified technical context, real-world timing roles, confirmed package mapping to 100-pin LQFP (14 mm × 14 mm), and validated alternatives for T1 framer/transceiver selection in carrier-grade infrastructure.

Technical Context

The DS21352L+ integrates independent transmit and receive paths with dual elastic stores supporting asynchronous backplane clocks up to 8.192 MHz, enabling seamless interfacing between T1 line rates (1.544 MHz) and 2.048 MHz E1 or bursty system clocks. Its framer complies with ANSI T1.403-1995, ITU G.703/G.704, and supports D4 (SLC-96) and ESF multiframe structures.

Line interface functionality includes programmable DSX-1 and CSU line build-outs (–7.5 dB, –15 dB, –22.5 dB), receive sensitivity from 0 dB to –36 dB for cables up to 6000 ft, and IEEE 1149.1 JTAG boundary scan. The device generates an 8.192 MHz clock locked to RCLK and supports per-channel loopback, idle code insertion, and in-band loop code generation/detection (1–8 bits).

Key Specifications

Pinout & Package

DS21352L+ is housed in a 100-pin LQFP package (14 mm × 14 mm, 0.5 mm pitch), with separate analog receive/transmit supplies (RVDD/TVDD), dual elastic store interfaces (RSYSCLK/TSYSCLK), JTAG test access (JTMS/JTCLK/JTDI/JTDO), and parallel control port supporting Intel/Motorola bus modes (BTS, MUX, D0–D7, A0–A6, RD*, WR*, CS*, INT*).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS21552L+, DS21352L+ reduces power by ~40% and eliminates external crystal dependency; compared with DS2152L+, it adds JTAG testability, elastic store clock flexibility, and hardware signaling acceleration - directly improving time-to-market and field serviceability.

Availability

DS21352L+ is available at Aetrix Electronics and suitable for central office line cards, ISDN-PRI gateways, remote terminal units, and T1 channel banks requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for DS21352L+ 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 U.S.-based semiconductor company specializing in precision analog, mixed-signal, and high-reliability interface ICs for communications, industrial, and automotive markets.

The DS21352L+ belongs to Maxim's SCT (Single-Chip Transceiver) family, designed specifically for carrier-class T1/E1 line interface applications requiring integrated framer, LIU, jitter control, and system-level timing robustness.

FAQ

What is the operating voltage range for DS21352L+?

The DS21352L+ operates from a single 3.3 V ±5% supply. It is not 5V-tolerant, and its I/O pins are designed for 3.3V logic levels. This makes DS21352L+ incompatible with 5V systems unless level translation is implemented. The DS21552L+ variant provides identical functionality at 5V.

Does DS21352L+ support both D4 and ESF framing formats?

Yes, DS21352L+ fully supports both D4 (SLC-96) and ESF multiframe structures. Its framer automatically detects and locks to either format, extracts robbed-bit signaling or FDL data, and monitors alarms including RLOS, RRA, and RAIS per ANSI T1.403-1995 and ITU G.704.

Can DS21352L+ drive long-haul T1 lines without external components?

Yes, DS21352L+ integrates a programmable line interface unit (LIU) capable of generating CSU line build-outs (–7.5 dB, –15 dB, –22.5 dB) and supports transformer-coupled connections to long-haul T1 lines up to 6000 feet. No external amplifiers or discrete line drivers are required.

Is DS21352L+ pin-compatible with earlier Maxim T1 transceivers?

Yes, DS21352L+ is pin-compatible with DS2152/DS2154/DS21354/DS21554 single-chip transceivers. This allows drop-in replacement in existing designs, preserving PCB layout while enabling access to new features like JTAG, interleaved PCM bus, and crystal-less jitter attenuation.

What clock frequencies does DS21352L+ support on its RSYSCLK and TSYSCLK inputs?

DS21352L+ accepts asynchronous backplane clocks up to 8.192 MHz on RSYSCLK and TSYSCLK, including standard rates of 1.544 MHz (T1), 2.048 MHz (E1), and bursty clocks. Elastic store operation is fully functional across this range, enabling flexible integration with diverse system clock domains.