Analog Devices Inc./Maxim Integrated DS2143N

Overview

DS2143N from Maxim Integrated (formerly Dallas Semiconductor) is a software-configurable E1 framing transceiver IC designed as a slave/coprocesor to microcontrollers in telecom line cards and ISDN-PRI access equipment. It performs full E1 frame alignment, CAS/CCS signaling extraction/insertion, CRC4 error detection/generation, HDB3 encoding/decoding, and supports 2.048 MHz primary clocking with 5V CMOS operation and 50 mW power dissipation.

For engineers reviewing the DS2143N datasheet, DS2143N pinout, DS2143N application, or DS2143N equivalent, this page delivers verified technical context on its dual-frame elastic store, parallel bus interface (Intel/Motorola configurable), Sa/Si bit handling, G.704/G.706/G.732 compliance, and role in E1 framer subsystems requiring precise timing, alarm monitoring, and drop-and-insert functionality.

Technical Context

The DS2143N implements an "off-line" framer architecture with fully independent receive and transmit paths, enabling transparent serial E1 stream pass-through while performing real-time framing, multiframe alignment (FAS/CRC4/CAS), and signaling processing. Its synchronizer detects frame/multiframe patterns per CCITT G.706 and supports programmable resync criteria for FAS, CRC4, and CAS modes.

It integrates a two-frame elastic store buffer with slip detection (SLIP flag), onboard Sa data link support circuitry, automatic E-bit generation, and local loopback capability. The parallel control port uses an 8-bit multiplexed AD0–AD7 bus with BTS-selectable Intel/Motorola timing, and supports register-level configuration of all functional blocks via 69 internal 8-bit registers.

Key Specifications

Pinout & Package

DS2143N is packaged in a 40-pin DIP (600-mil), pin-compatible with DS2141A T1 Controller and functionally aligned with DS2143Q (44-pin PLCC variant). All pin functions are validated per official DS2143/DS2143Q datasheet Rev. 04/2001.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2143N, DS2141A serves only T1 systems and omits E1-specific signaling and compliance, while SI2143 offers identical functionality with improved robustness and extended temperature support-making it the preferred upgrade path for long-lifecycle telecom hardware.

Availability

DS2143N is available at Aetrix Electronics and suitable for ISDN-PRI gateways, E1 line cards, and fractional E1 drop-and-insert nodes requiring stable component supply across multi-year production cycles.

Supply support for DS2143N 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 (acquired by Analog Devices in 2021) is a semiconductor company specializing in precision analog, mixed-signal, and power management ICs for communications, industrial, and computing markets.

The DS2143N belongs to Maxim's legacy telecom timing and interface product line, engineered specifically for E1 framer applications in carrier-class access equipment, PBX systems, and protocol-aware network probes.

FAQ

What is the primary function of the DS2143N in an E1 system?

The DS2143N acts as a software-configurable E1 framing transceiver that performs frame alignment, CAS/CCS signaling extraction and insertion, CRC4 error detection/generation, and HDB3 encoding/decoding. It operates as a coprocessor to a host microcontroller, managing the physical layer framing tasks while passing the E1 serial stream unchanged-enabling precise timing, alarm monitoring, and flexible configuration in telecom line cards and ISDN-PRI equipment. DS2143N supports full G.704/G.706/G.732 compliance and integrates a two-frame elastic store for clock domain bridging.

Does the DS2143N support both CAS and CCS signaling modes?

Yes, the DS2143N supports both Channel Associated Signaling (CAS) and Common Channel Signaling (CCS) modes. This is controlled via the Receive Signaling Mode Select bit (CCR.3): setting it to 0 configures CAS mode (e.g., for timeslot 16 bit extraction), while setting it to 1 enables CCS mode. The device provides full access to Sa and Si bits in both configurations and handles multiframe alignment per G.732 for CAS and G.706 for CRC4-based CCS. DS2143N's register-level control allows runtime switching between these modes without hardware changes.

How does the elastic store in the DS2143N handle clock mismatches?

The DS2143N incorporates a two-frame elastic store buffer that absorbs short-term clock frequency differences between the incoming E1 line clock (RCLK) and the system clock domain. When the buffer fills, it deletes a frame (reported via ESF flag in RIR); when it empties, it repeats a frame (reported via ESE flag). Slip events are flagged in Status Register 1 (SLIP bit, SR1.4). This mechanism maintains data continuity during minor clock drift-critical for jitter-tolerant E1 interfaces. DS2143N allows the elastic store to be enabled or bypassed via RCR2.1, and SYSCLK must be supplied (1.544/2.048 MHz) when enabled.

Can the DS2143N operate with Intel- and Motorola-style microprocessor buses?

Yes, the DS2143N supports both Intel- and Motorola-style parallel bus timing through the BTS (Bus Type Select) pin. Strapping BTS low configures the device for Intel timing (using RD, WR, CS, ALE signals), while strapping it high selects Motorola timing (using DS, R/W, CS, AS). The AD0–AD7 bus is multiplexed for address and data, with ALE(AS) latching the address phase. This dual-bus compatibility simplifies integration with diverse host processors without additional glue logic. DS2143N's register map and control flow remain identical regardless of bus mode selection.

What alarm conditions does the DS2143N monitor and report?

The DS2143N monitors and reports over a dozen real-time alarm conditions including Receive Loss of Sync (RLOS), Loss of Receive Clock (LORC), Loss of Transmit Clock (LOTC), Remote Alarm (RRA), Signaling All 1s (RSA1), Signaling All 0s (RSA0), Distant Multiframe Alarm (RDMA), Carrier Loss (RCL), Unframed All 1s (RUA1), and CRC4/E-bit errors. Alarms are latched in Status Registers 1 and 2 and can trigger hardware interrupts on INT1/INT2 pins. Each alarm has defined set/clear criteria per ITU standards (e.g., G.732, O.162), and DS2143N provides dedicated counter registers (e.g., E-Bit Count Registers 1–2) for statistical analysis.