Analog Devices Inc./Maxim Integrated DS21354LB

Overview

DS21354LB from Maxim Integrated (now Analog Devices) is a 3.3V single-chip E1 transceiver IC designed for CEPT PCM-30/ISDN-PRI line interface applications. It integrates clock/data recovery, jitter attenuation (32-bit or 128-bit selectable), framer with FAS/CAS/CCS/CRC4 support, HDLC controller with 64-byte buffers, and dual elastic stores - all in a 100-pin LQFP package. It operates over 0–2 km of 22AWG twisted-pair cable with receive sensitivity down to –43 dB.

For engineers reviewing the DS21354LB datasheet, DS21354LB pinout, DS21354LB application, or DS21354LB equivalent, this device serves as a drop-in upgrade to DS2154/DS2153 in telecom access equipment requiring G.703/G.704/G.823-compliant E1 framing, hardware-based signaling, and JTAG boundary-scan testability.

Technical Context

The DS21354LB implements a fully independent transmit and receive data path with separate elastic stores synchronized to asynchronous backplane clocks (up to 8.192 MHz). Its framer detects and generates FAS, CAS, CRC4, AIS, RAI, RLOS, and carrier loss alarms while extracting/inserting Si and Sa bits aligned to CRC-4 multiframe boundaries.

Line interface functionality is decoupled from framing logic, enabling monitoring of bipolar data streams and compatibility with optical, HDSL, or NRZ interfaces. The crystal-less jitter attenuator can be placed in either path, and the IEEE 1149.1 JTAG port supports boundary-scan testing without requiring external clock sources.

Key Specifications

Pinout & Package

DS21354LB is housed in a 100-pin LQFP package (14 mm × 14 mm, 0.5 mm pitch), RoHS-compliant and rated for industrial temperature range (–40°C to +85°C) per DS21354LN variant; DS21354LB denotes same package with lead-free finish and tape-and-reel packaging.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar E1 transceiver applications.

Compared with DS2154L, DS21354LB adds 3.3V operation, JTAG testability, and hardware HDLC - critical for new deployments. Unlike MAX3089CSE+, DS21354LB delivers complete E1 transceiver functionality including clock recovery, framing, and line driving per ITU-T standards.

Availability

DS21354LB is available at Aetrix Electronics and suitable for telecom access multiplexers, ISDN-PRI gateways, remote alarm monitoring units, and carrier-class DSLAM line cards requiring stable component supply and long-term lifecycle support.

Supply support for DS21354LB 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

Analog Devices (acquired Maxim Integrated in 2021) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving communications, industrial, and automotive markets.

The DS21354LB belongs to Maxim's legacy E1/PCM transceiver product line, engineered specifically for carrier-grade telecom infrastructure requiring G.703/G.704 compliance, hardware signaling, and robust jitter management.

FAQ

What is the operating voltage range for DS21354LB?

The DS21354LB operates at a nominal 3.3V supply with ±5% tolerance (3.135V to 3.465V). It is not compatible with 5V logic or supply rails. This voltage level aligns with modern low-power telecom line cards and enables direct interfacing with 3.3V FPGA or microcontroller parallel control ports without level-shifting circuitry. DS21354LB maintains full functionality across its specified industrial temperature range (–40°C to +85°C) under this supply condition.

Does DS21354LB support both 75Ω coaxial and 120Ω twisted-pair E1 interfaces?

Yes, DS21354LB supports both 75Ω coaxial and 120Ω twisted-pair line interfaces per ITU-T G.703. Its transmit line driver generates compliant waveshapes for both media types, and the receive side accepts transformer-coupled inputs from either. Configuration is handled via internal Line Interface Control Register (LICR) settings - Table 15-2 in the datasheet specifies DS21354L-specific line build-out selections for optimal impedance matching and rise/fall time control on each medium.

How does DS21354LB handle E1 framing and multiframe alignment?

DS21354LB's framer locates frame (FAS) and multiframe (CAS, CCS, CRC4) boundaries in real time using hardware state machines. It supports all standard E1 formats: FAS, CAS, CCS, and CRC4. Multiframe alignment is maintained with full access to Si and Sa bits synchronized to CRC-4 multiframe structure. The device also provides large error counters for BPV, CRC4 codeword errors, FAS word errors, and E-bits - accessible via parallel port registers for performance monitoring and alarm generation.

Can DS21354LB operate without an external crystal oscillator?

Yes, DS21354LB features a crystal-less jitter attenuator that functions without any external crystal. It uses internal RC-based timing with digital calibration to achieve jitter attenuation depths of 32 bits or 128 bits - selectable via register configuration. This eliminates BOM cost and board space associated with external crystals while meeting G.823 jitter tolerance requirements for E1 applications. An optional 32.768 MHz crystal may be added for enhanced stability if needed.

Is DS21354LB pin-compatible with earlier Maxim E1 transceivers?

DS21354LB is pin-compatible with DS2154/DS2152/DS21352/DS21552 single-chip transceivers in the same 100-pin LQFP package. This allows direct PCB replacement in existing designs, provided the 3.3V supply and updated firmware accommodate new features like JTAG, HDLC, and interleaved PCM bus operation. No layout changes are required, but register initialization sequences must be updated to leverage enhanced functionality of DS21354LB.