Analog Devices Inc./Maxim Integrated DS21354LN

Overview

DS21354LN from Maxim Integrated is a 3.3V single-chip E1 transceiver (SCT) designed for CEPT PCM-30/ISDN-PRI line interface applications. It integrates clock/data recovery from AMI/HDB3 E1 waveforms, jitter attenuation (32-bit or 128-bit selectable), framer with FAS/CAS/CCS/CRC4 support, HDLC controller for Sa-bit or DS0 channels, and dual elastic store buffers. It operates across -40°C to +85°C and meets ITU-T G.703/G.704/G.706/G.823, ETS 300 011/233/166, and CTR12/CTR4 standards.

For engineers reviewing the DS21354LN datasheet, DS21354LN pinout, DS21354LN application, or DS21354LN equivalent, this device serves as a temperature-hardened, pin-compatible upgrade to the DS2154 for E1 line cards requiring robust long-haul cable support (0–2km), programmable output clocks for fractional E1/H0/H12, and IEEE 1149.1 JTAG boundary scan testability.

Technical Context

The DS21354LN implements a fully independent transmit and receive path architecture with separate elastic stores synchronized to asynchronous backplane clocks up to 8.192MHz. Its on-chip clock/data recovery circuitry supports AMI/HDB3 waveform decoding from twisted-pair cables, while the crystal-less jitter attenuator can be placed in either path and configured for 32-bit or 128-bit depth.

It features hardware-based signaling reinsertion aligned with multiframe sync, dedicated Si/Sa bit access in CRC-4 multiframe, and four distinct loopback modes (framer, remote, local, per-channel). The parallel control port supports both multiplexed and nonmultiplexed Intel/Motorola buses without external glue logic.

Key Specifications

Pinout & Package

DS21354LN is housed in a 100-pin LQFP package (14mm × 14mm, 0.5mm pitch), thermally optimized for telecom line card PCB layouts with high-density interconnects and thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2154LN, DS21354LN adds HDLC offload, JTAG testability, and flexible clock synthesis - critical for new designs targeting reduced firmware load and production test coverage. No functional alternative exists in Silicon Labs' lineup, confirming DS21354LN's unique integration level for industrial E1 applications.

Availability

DS21354LN is available at Aetrix Electronics and suitable for telecom line cards, E1 multiplexers, industrial remote I/O gateways, and test & measurement equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for DS21354LN 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 high-performance analog, mixed-signal, and power management ICs for communications, industrial, and computing markets.

The DS21354LN belongs to Maxim's Single-Chip Transceiver (SCT) product line, engineered specifically for CEPT/E1 line interface applications demanding full G.703/G.704 compliance, extended temperature operation, and integrated framer/signaling functionality.

FAQ

What is the operating voltage range for the DS21354LN?

The DS21354LN operates from a single 3.3V ±5% supply rail. This fixed-voltage requirement distinguishes it from the 5V DS21554 variant and ensures compatibility with modern low-voltage telecom system power architectures. All internal logic, analog front-end, and I/O buffers are designed for 3.3V operation - no dual-supply configuration or level-shifting is needed when interfacing with 3.3V controllers. DS21354LN does not support 5V operation.

Does the DS21354LN support both 75Ω coaxial and 120Ω twisted-pair E1 interfaces?

Yes, the DS21354LN supports both 75Ω coaxial and 120Ω twisted-pair E1 line interfaces through programmable line build-out (LBO) settings in the Line Interface Control Register (LICR). Configuration is done via its parallel control port, allowing dynamic switching between impedance types without hardware changes. Transformer coupling remains mandatory, and reference designs specify appropriate wideband pulse transformers meeting G.703 return loss requirements.

How does the DS21354LN handle jitter attenuation without an external crystal?

The DS21354LN implements an on-chip crystal-less jitter attenuator with selectable 32-bit or 128-bit depth, using internal PLL/VCO circuitry locked to the recovered E1 clock. This eliminates the need for an external crystal while maintaining jitter transfer compliance per ITU-T G.823. The attenuator can be placed in either the transmit or receive data path via register control, enabling precise phase-noise filtering before line driving or after clock recovery.

Can the DS21354LN operate with asynchronous backplane clocks?

Yes, the DS21354LN includes dual independent elastic store buffers - one on the receive side and one on the transmit side - each synchronized to its own asynchronous backplane clock (RSYSCLK or TSYSCLK). These clocks may run at 1.544MHz, 2.048MHz, 4.096MHz, or 8.192MHz and need not be phase-locked to the E1 line clock. This architecture absorbs frequency/phase differences between line and system domains, enabling seamless integration into heterogeneous timing environments.

Is the DS21354LN pin-compatible with earlier Maxim E1 transceivers?

Yes, the DS21354LN is pin-compatible with the DS2154, DS2152, DS21352, and DS21552 single-chip transceivers in the same 100-pin LQFP package. This allows direct PCB-level replacement in existing designs, provided firmware is updated to leverage new features like HDLC offload, JTAG, and enhanced alarm reporting. Pin mapping for RRING/RTIP, TRING/TTIP, D0–D7, and control signals remains identical across all compatible variants.