Analog Devices Inc./Maxim Integrated DS21554LBN+

Overview

DS21554LBN+ from Maxim Integrated is a 5V single-chip E1 transceiver (SCT) implementing full CEPT PCM-30/ISDN-PRI line interface functionality, including AMI/HDB3 clock/data recovery, G.703 waveshaping for 75Ω coax and 120Ω twisted-pair, 32-/128-bit crystal-less jitter attenuation, FAS/CAS/CRC4 framing, and integral HDLC controller with 64-byte buffers. It operates across -40°C to +85°C in 100-pin LQFP and supports dual elastic store slip buffers for asynchronous backplane interfacing up to 8.192MHz.

For engineers reviewing the DS21554LBN+ datasheet, DS21554LBN+ pinout, DS21554LBN+ application, or DS21554LBN+ equivalent, key selection criteria include E1 line interface compliance (ITU-T G.703/G.704/G.706/G.823, ETS 300 011/233/166), programmable output clocks for fractional E1/H0/H12, IEEE 1149.1 JTAG boundary scan, and pin compatibility with DS2154/52/352/552 SCTs.

Technical Context

The DS21554LBN+ integrates independent transmit and receive signal paths with dedicated framer/formatter blocks, each supporting configurable frame alignment (FAS), multiframe synchronization (CRC4), and signaling extraction/insertion (CAS, Sa, Si). Its on-chip jitter attenuator-selectable between 32-bit and 128-bit depth-is placed in either path via internal mux, enabling precise phase noise suppression without external crystal.

Line interface operation includes transformer-coupled analog input (RRING/RTIP), active filter compensation for nonlinear cable loss, and programmable line build-out (LBO) per Table 15-1 for 0–2km 22AWG twisted-pair. The 8.192MHz clock synthesizer and dual elastic stores allow seamless bridging between recovered E1 timing and asynchronous system clocks (1.544/2.048/4.096/8.192MHz).

Key Specifications

Pinout & Package

DS21554LBN+ is housed in a 100-pin LQFP package (14mm × 14mm, 0.5mm pitch), RoHS-compliant and moisture-sensitive level 3. Pin functions are validated per Maxim's official DS21354/DS21554 datasheet Rev 021004, Sections 3.1.1–3.1.7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS21554L+ and DS21354LBN+, the DS21554LBN+ uniquely combines industrial temperature range, 5V operation, and MSL3 packaging - making it the sole option for ruggedized E1 edge deployments where voltage stability and environmental resilience are co-dependent requirements.

Availability

DS21554LBN+ is available at Aetrix Electronics and suitable for telecom access nodes, enterprise PRI gateways, mobile base station controllers, and industrial remote terminal units requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for DS21554LBN+ 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 RF ICs for communications, computing, and industrial markets.

The DS21554LBN+ belongs to Maxim's Single-Chip Transceiver (SCT) product line, engineered specifically for CEPT/E1 line interface applications in carrier-grade and industrial telecom infrastructure where integration, standards compliance, and timing integrity are critical.

FAQ

What is the operating voltage range for DS21554LBN+?

The DS21554LBN+ operates at a nominal 5V supply with ±5% tolerance (4.75V to 5.25V), as specified in the Maxim DS21354/DS21554 datasheet Rev 021004 Section 19. This 5V requirement distinguishes it from the 3.3V DS21354LBN+ variant and ensures compatibility with legacy telecom power domains. DS21554LBN+ does not support dual-supply or voltage scaling.

Does DS21554LBN+ support both E1 and T1 framing formats?

DS21554LBN+ is designed exclusively for E1 (2.048Mbps) applications and fully complies with ITU-T G.703/G.704/G.706 and ETSI standards. While it accepts 1.544MHz backplane clocks (e.g., for T1-compatible timing), its framer is hardwired for 32-slot E1 frames with FAS/CRC4 alignment - it does not support T1-specific D4/SF framing or ESF checksums. DS21554LBN+ cannot be reconfigured for native T1 operation.

How is jitter attenuation implemented in DS21554LBN+?

DS21554LBN+ implements crystal-less jitter attenuation using an on-chip digital phase-locked loop (DPLL) with selectable 32-bit or 128-bit buffer depth, as detailed in Section 15.3 of the datasheet. The attenuator can be routed into either the transmit or receive data path via register control, meeting ITU-T G.823 jitter transfer requirements without external components. DS21554LBN+ does not require a crystal oscillator for this function.

Is DS21554LBN+ pin-compatible with older Maxim SCTs?

Yes, DS21554LBN+ is explicitly pin-compatible with DS2154, DS2152, DS21352, and DS21552 single-chip transceivers, as confirmed in the "Features" section of the datasheet. This allows drop-in replacement in existing PCB layouts, preserving mechanical fit, thermal profile, and signal routing - provided the 5V supply and -40°C to +85°C operating range align with system requirements.

What alarm conditions does DS21554LBN+ detect and report?

DS21554LBN+ detects and reports RLOS (Receive Loss of Signal), RRA (Remote Alarm Indication), RAIS (Remote Alarm Indication – Superframe), AIS (Alarm Indication Signal), and carrier loss (RCL) conditions. Per Section 6.1 and Table 6-1, these alarms generate status flag changes and optional interrupts. DS21554LBN+ also supports automatic AIS generation per ETS 300 011 and configurable alarm response timing per ETS 300 233.