Analog Devices Inc./Maxim Integrated DS2143Q+

Overview

DS2143Q+ from Maxim Integrated (formerly Dallas Semiconductor) is an E1 framing transceiver IC designed as a software-configurable slave/coprocesor for microcontroller-based telecom line cards. It performs full E1 frame alignment, CAS/CCS signaling extraction and insertion, CRC4 error detection/generation, HDB3 encoding/decoding, and supports fractional E1 drop-and-insert applications with programmable output clocks. It operates at 5 V and consumes 50 mW.

For engineers reviewing the DS2143Q+ datasheet, DS2143Q+ pinout, DS2143Q+ application, or DS2143Q+ equivalent, this page delivers verified technical context, exact register-mapped functionality, elastic store behavior, alarm handling logic, and real-world interface constraints - all grounded in the official DS2143/DS2143Q datasheet Rev 44.

Technical Context

The DS2143Q+ implements a dual-path "off-line" framer architecture: its receive side fully synchronizes to incoming E1 streams via RPOS/RNEG, detects FAS/CRC4/CAS multiframe boundaries per ITU-T G.704/G.706/G.732, and feeds aligned data into a two-frame elastic store (bypassable). Its transmit side accepts unframed serial data at TSER, inserts framing, signaling, and Sa/Si bits, and outputs bipolar or NRZ data via TPOS/TNEG.

Control is executed through a multiplexed 8-bit AD0–AD7 bus supporting both Intel and Motorola timing (selected by BTS), with 69 internal registers governing framing mode, slip buffer behavior, alarm masking (INT1/INT2), HDB3 enable, CRC4/E-bit generation, and Sa bit routing. The device provides dedicated hardware for FEBE E-bit counting, remote alarm detection, and local loopback (LLB) for diagnostics.

Key Specifications

Pinout & Package

DS2143Q+ is packaged in a 44-pin PLCC (plastic leaded chip carrier), 16.5 mm × 16.5 mm body, 1.27 mm pitch. Pin 1 is located at the corner adjacent to the index mark.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2141A and XR2206, the DS2143Q+ uniquely combines software-reconfigurable framing, two-frame elastic store with slip reporting, and full Sa/Si bit handling - making it optimal for scalable, standards-compliant E1 line interface cards requiring field-upgradable features.

Availability

DS2143Q+ is available at Aetrix Electronics and suitable for telecom infrastructure, ISDN-PRI access equipment, and E1 test instrumentation requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for DS2143Q+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and RF solutions for communications, industrial, and computing markets.

The DS2143Q+ belongs to Maxim's legacy telecom timing and framing portfolio, designed specifically for E1 line interface applications requiring standards-compliant, microcontroller-driven framer functionality with minimal external components.

FAQ

What is the primary function of the DS2143Q+ in an E1 system?

The DS2143Q+ serves as a software-configurable E1 framing transceiver that performs frame alignment, CAS/CCS signaling extraction and insertion, CRC4 error detection/generation, HDB3 encoding/decoding, and elastic store buffering. It interfaces with a host microcontroller via an 8-bit multiplexed bus and supports both Intel and Motorola timing protocols. The DS2143Q+ does not include a line driver; it must be paired with an external line interface device such as the DS2174 or similar.

Does the DS2143Q+ support both CAS and CCS signaling modes?

Yes, the DS2143Q+ supports both Channel Associated Signaling (CAS) and Common Channel Signaling (CCS) modes. The Receive Signaling Mode Select bit (RSM in CCR.3) configures the device to process timeslot 16 either as CAS (bit-oriented) or CCS (Sa/Si bit-oriented). In CCS mode, the DS2143Q+ provides full access to Sa bits (Sa4–Sa8) and Si bits via RLINK/TLINK and internal registers, complying with ITU-T G.732 Annex A.

How does the elastic store in the DS2143Q+ handle clock domain mismatches?

The DS2143Q+ includes a two-frame deep elastic store that buffers incoming E1 frames to absorb timing differences between the line clock (RCLK) and system clock domains. When enabled (RCR2.1 = 1), it dynamically repeats or deletes frames to maintain alignment - signaled via SLIP flag in SR1 and ESF/ESE bits in RIR. The store requires SYSCLK (1.544 or 2.048 MHz) and is bypassed when RCR2.1 = 0 for synchronous applications.

Can the DS2143Q+ generate and detect CRC4 E-bits automatically?

Yes, the DS2143Q+ supports automatic CRC4 E-bit generation and detection. Transmit CRC4 is enabled via TCRC4 (CCR.4), and receive CRC4 via RCRC4 (CCR.0). The AEBE bit (TCR2.1) enables automatic E-bit insertion in transmit mode. CRC4 error counts are stored in registers 02h–03h, and multiframe sync status is reported in SSR. CRC4 operation complies fully with ITU-T G.706 Section 4.3.

What are the key differences between DS2143Q+ and the older DS2141A?

The DS2143Q+ is pin-compatible with the DS2141A but adds significant enhancements: onboard Sa data link support circuitry, G.802 E1-to-T1 mapping capability, full CAS multiframe alignment per G.732, enhanced alarm granularity (e.g., SLIP, RSA1/RSA0), and expanded register set (69 vs. 48 registers). The DS2143Q+ also improves elastic store control and provides more flexible interrupt masking via IMR1/IMR2 - making it suitable for next-generation E1 line cards.