Analog Devices Inc./Maxim Integrated DS2182Q

Overview

DS2182Q from Maxim Integrated (now Analog Devices) is a monolithic CMOS T1 line monitor IC designed for real-time framing, error counting, and status reporting on T1 telecommunications lines. It supports both Superframe (193S) and Extended Superframe (193E) formats, features four on-board error counters (16-bit bipolar violation, 8-bit CRC, 8-bit OOF, 8-bit frame bit error), and operates from a single 5V supply. It is used in central office line cards, channel banks, and T1 repeater monitoring systems.

For engineers reviewing the DS2182Q datasheet, DS2182Q pinout, DS2182Q application, or DS2182Q equivalent, key selection considerations include its 28-pin PLCC package, ANSI T1.231 compliance, support for B8ZS/AMI line coding, burst-mode serial interface for rapid counter polling, and integrated alarm outputs (RLOS, RYEL, RBV, RFER) with latched status registers.

Technical Context

The DS2182Q implements a dual-buffered serial port interface synchronized to SCLK (input) and operating asynchronously with the 1.544MHz RCLK input, enabling non-disruptive register access during live line monitoring. Its receive synchronizer performs off-line resync with configurable criteria (RCR1.3/RCR1.2), supporting 10- or 24-bit framing pattern validation and CRC6-assisted alignment verification in 193E mode.

It integrates dedicated hardware for real-time detection of yellow/blue alarms, carrier loss (192 consecutive zeros), 8/16-zero strings, change-of-frame alignment, and B8ZS codewords - all reported via latched status bits (RSR1/RSR2) and open-drain interrupt (INT). The auto-counter reset feature (RCR1.4) enables atomic read-and-clear of all four error counters in burst mode.

Key Specifications

Pinout & Package

DS2182Q is housed in a 28-pin Plastic Leaded Chip Carrier (PLCC) package with J-leads, compatible with standard PLCC sockets and reflow soldering profiles for telecom PCB assemblies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar T1 line monitoring applications.

Compared with DS2182N and DS2182, the DS2182Q provides identical core T1 monitoring capability in a commercial-temperature PLCC package while incorporating documented improvements in alarm detection fidelity and diagnostic granularity - making it the preferred choice for new commercial-grade telecom equipment designs.

Availability

DS2182Q is available at Aetrix Electronics and suitable for central office line monitoring, T1 channel bank diagnostics, DSLAM backhaul monitoring, and T1 repeater site alarm systems requiring stable component supply across multi-year production cycles.

Supply support for DS2182Q 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 high-performance analog, mixed-signal, and power management solutions for communications, computing, and industrial markets.

The DS2182Q belongs to Maxim's legacy telecom line interface IC product line, engineered specifically for T1/E1 physical layer monitoring, framing, and alarm generation in carrier-grade infrastructure equipment.

FAQ

What is the primary function of the DS2182Q in a T1 system?

The DS2182Q serves as a dedicated T1 line monitor IC that performs real-time framing synchronization, error counting (bipolar violations, CRC, OOF, frame bit errors), and alarm generation (yellow, blue, loss-of-sync, carrier loss) for 1.544Mbps T1 lines. It extracts timing signals like RFSYNC and RMSYNC and provides status via serial interface and discrete outputs - all without requiring host CPU intervention during normal operation.

Does the DS2182Q support both Superframe and Extended Superframe formats?

Yes, the DS2182Q supports both Superframe (193S, 12-frame) and Extended Superframe (193E, 24-frame) formats. Format selection is controlled by bit RCR2.4 in the Receive Control Register 2: setting it to 0 selects 193S mode, and setting it to 1 selects 193E mode. The device automatically adapts counter behavior, CRC checking, and alarm logic based on the selected format.

How does the DS2182Q handle resynchronization after loss of frame alignment?

The DS2182Q implements an off-line resync engine that searches for valid framing patterns while maintaining previous timing outputs. Resync behavior is configurable via RCR1 bits: RCR1.2 sets sync validation depth (10 or 24 bits), RCR1.3 enables CRC6-assisted alignment in 193E mode, and RCR1.7 determines whether resync triggers on OOF events only or also on carrier loss. A high-to-low transition on RST forces immediate resync.

Can the DS2182Q count excessive zero sequences, and how is this configured?

Yes, the DS2182Q can count excessive zero sequences - eight consecutive zeros when B8ZS is enabled, or sixteen consecutive zeros when B8ZS is disabled. This function is enabled by setting bit RCR2.5 (BVCRF) in Receive Control Register 2. When enabled, the 16-bit Bipolar Violation Count Register (BVCR) increments for each qualifying zero string, independent of bipolar violation detection.

What is the role of the burst mode feature in the DS2182Q serial interface?

The burst mode in the DS2182Q serial interface allows the host controller to read or write all 11 internal registers consecutively in a single CS-low transaction. When enabled (ACB.7 = 1 and address = 0000), burst mode minimizes initialization time and enables atomic status polling. Crucially, if RCR1.4 (Auto Counter Reset) is set, a burst read automatically resets all four error counters - ensuring consistent, race-free status capture.