Analog Devices Inc./Maxim Integrated DS21354L+

Overview

DS21354L+ from Maxim Integrated is a 3.3V single-chip E1 transceiver (SCT) implementing full CEPT PCM-30/ISDN-PRI line interface functionality, with on-board clock/data recovery for AMI/HDB3 waveforms, 32-bit or 128-bit crystal-less jitter attenuation, and integrated HDLC controller supporting Sa-bit links or DS0 channels. It operates over 0–2 km of 22AWG twisted-pair cable and meets ITU-T G.703/G.704/G.706/G.823 and ETS 300 011/233/166 standards in telecom access equipment.

For engineers reviewing the DS21354L+ datasheet, DS21354L+ pinout, DS21354L+ application, or DS21354L+ equivalent, key selection criteria include E1 framer alignment to FAS/CAS/CCS/CRC4 formats, dual elastic store support for asynchronous backplane interfacing up to 8.192MHz, IEEE 1149.1 JTAG boundary scan capability, and programmable output clocks for fractional E1, H0, and H12 timing synthesis.

Technical Context

The DS21354L+ integrates independent transmit and receive paths with dedicated framer/formatter logic, enabling simultaneous framing analysis and generation without shared clock constraints. Its receive-side framer locates frame (FAS) and multiframe (CRC4/CAS) boundaries while detecting RLOS, RCL, AIS, and remote alarm conditions - all with interrupt-on-change capability for RCL, RLOS, RRA, and RAIS.

Transmit-side functionality includes per-channel code insertion, hardware-based signaling reinsertion into backplane multiframe sync, and independent elastic store clocks (RSYSCLK/TSYSCLK), supporting interleaved PCM bus operation in byte or frame mode at 2.048MHz, 4.096MHz, or 8.192MHz system clock rates.

Key Specifications

Pinout & Package

DS21354L+ is housed in a 100-pin LQFP package (14mm × 14mm), RoHS-compliant and optimized for high-density telecom line card layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2154L+ and MC145508FN, the DS21354L+ delivers superior integration for modern E1 edge devices - combining crystal-less jitter attenuation, JTAG testability, and hardware-accelerated signaling in a single 3.3V LQFP package - reducing BOM count and PCB area while improving timing robustness.

Availability

DS21354L+ is available at Aetrix Electronics and suitable for telecom access multiplexers, ISDN PRI gateways, remote terminal units, and network monitoring taps requiring stable component supply and long-term lifecycle support.

Supply support for DS21354L+ 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 power management ICs for industrial, communications, and computing markets.

The DS21354L+ belongs to Maxim's E1/T1 transceiver product line, designed specifically for carrier-grade telecom infrastructure requiring high-reliability line interface, precise jitter control, and embedded protocol handling in compact form factors.

FAQ

What voltage supply does the DS21354L+ require?

The DS21354L+ operates exclusively from a 3.3V ±5% supply rail. Unlike the pin-compatible DS21554L+, it is not rated for 5V operation. This lower voltage enables reduced power consumption and compatibility with modern 3.3V control-plane architectures in telecom line cards. The DS21354L+ internal regulators and I/O buffers are optimized for this supply level, and applying 5V will damage the device.

Does the DS21354L+ support both FAS and CRC4 multiframe alignment?

Yes, the DS21354L+ fully supports frame alignment to FAS (Frame Alignment Signal) and multiframe alignment to CRC4, CAS, and CCS formats as defined in ITU-T G.704 and G.706. Its framer logic autonomously detects and locks to these structures in incoming E1 streams, and the DS21354L+ registers provide status flags and interrupt capability for loss-of-frame and loss-of-multiframe events.

Can the DS21354L+ generate its own 8.192MHz system clock?

Yes, the DS21354L+ integrates an on-chip 8.192MHz clock synthesizer that can operate without an external crystal. This feature is enabled via configuration registers and works in conjunction with its crystal-less jitter attenuator. The DS21354L+ uses internal PLL circuitry referenced to either an external 32.768kHz or 16.384kHz crystal, eliminating the need for a discrete 8.192MHz oscillator in timing-critical backplane interfaces.

How many loopback modes does the DS21354L+ support, and what are they used for?

The DS21354L+ supports four distinct loopback modes: framer loopback, remote loopback, local loopback, and per-channel loopback. These are used for layered diagnostics - framer loopback verifies internal digital path integrity; remote loopback tests end-to-end line health including far-end transceiver; local loopback checks transmit/receive interface functionality; and per-channel loopback isolates individual DS0 channels for targeted fault isolation during commissioning or maintenance of the DS21354L+.

Is the DS21354L+ pin-compatible with earlier Maxim E1 transceivers?

Yes, the DS21354L+ is pin-compatible with the DS2154/DS2152/DS21352/DS21552 single-chip transceivers, sharing identical 100-pin LQFP footprint and signal mapping. This allows drop-in replacement in existing designs while adding new capabilities such as crystal-less jitter attenuation, JTAG boundary scan, and interleaved PCM bus operation - provided the host firmware and power delivery are updated to support the DS21354L+'s 3.3V requirement and enhanced register set.