Analog Devices Inc./Maxim Integrated DS2174Q

Overview

DS2174Q from Maxim Integrated is a software-programmable enhanced bit error-rate tester (EBERT) IC for telecom transmission validation, featuring 48-bit bit/error counters, pseudorandom pattern generation up to 2³²−1, user-defined repetitive patterns up to 512 bytes, serial/nibble/byte data interfaces, and operation at up to 155MHz transmit clock rate in 44-pin PLCC packaging. It serves as a core test engine in CSU/DSU and digital mux diagnostics.

For engineers reviewing the DS2174Q datasheet, DS2174Q pinout, DS2174Q application, or DS2174Q equivalent, this page delivers verified functional identity, exact interface timing constraints, confirmed pattern synchronization behavior, real-world BER detection limits (up to 10⁻²), and validated alternative options for telecom bit-error testing systems.

Technical Context

The DS2174Q implements independent, fully programmable transmit and receive paths with hardware-accelerated pattern detection logic. Its polynomial generator uses a 32-tap programmable feedback shift register with seed preload capability, supporting industry-standard polynomials including QRSS (2²⁰−1 with 14-zero suppression per T1.403).

Synchronization is adaptive: polynomial sync completes in 50 + n cycles (n = exponent), while repetitive pattern sync requires ≥1 full error-free repetition; loss-of-sync triggers on 6 errors in 64 bits. Bit error insertion is hardware-controlled via Control Register 2 with discrete error rates from 10⁻¹ to 10⁻⁷, with mode-dependent scaling in nibble/byte modes.

Key Specifications

Pinout & Package

DS2174Q is housed in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with gull-wing leads, designed for surface-mount assembly and thermal reliability in telecom test equipment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bit error-rate testing applications.

Compared with DS2174Q, DS2175Q offers identical core BERT functionality plus JTAG and wider temperature tolerance-making it suitable for harsh environments-but MAX3675 serves a fundamentally different domain (Ethernet PHY) and lacks the DS2174Q's telecom-specific features like QRSS, 155MHz serial operation, and 48-bit counters.

Availability

DS2174Q is available at Aetrix Electronics and suitable for channel service units (CSUs), data service units (DSUs), and digital multiplexers requiring stable component supply for telecom infrastructure test instrumentation.

Supply support for DS2174Q 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 semiconductor company specializing in precision analog, mixed-signal, and high-speed communication ICs for industrial, telecom, and computing markets.

The DS2174Q belongs to Maxim's Telecom Test & Measurement product line, engineered specifically for bit-level validation of TDM, SONET, and PDH digital transmission systems with hardware-accelerated pattern generation and error analysis.

FAQ

What is the maximum pseudorandom pattern length supported by the DS2174Q?

The DS2174Q supports pseudorandom pattern generation up to 2³²−1, enabled by its 32-bit programmable tap select register and seed preload capability. This covers all industry-standard polynomials-including O.151 (2¹⁵−1), O.152 (2¹¹−1), QRSS (2²⁰−1), and maximal-length sequences-and is confirmed in the General Description and Table 3-C of the DS2174Q datasheet.

Does the DS2174Q support QRSS pattern generation per T1.403?

Yes, the DS2174Q natively supports QRSS (2²⁰−1) pattern generation with hardware-enforced 14-zero suppression as defined in T1.403. Setting the QRSS bit (CR1.3) activates this rule, ensuring that an output bit is forced to 1 whenever the next 14 bits would otherwise be zero-a requirement explicitly documented in Section 1.1.1 and Table 3-C of the DS2174Q datasheet.

What are the valid data interface modes for the DS2174Q and how are they selected?

The DS2174Q supports three data interface modes: bit-serial, 4-bit nibble-parallel, and 8-bit byte-parallel. Mode selection is controlled by MODE1/MODE0 bits in Control Register 2 (Address 01h), with combinations 00=bit, 01=nibble, 10=byte. The RDAT/TDAT pins adapt automatically-e.g., RDAT0 alone for serial, RDAT0–3 for nibble, RDAT0–7 for byte-as detailed in Section 3.1 and Table 3-A of the DS2174Q datasheet.

How does the DS2174Q handle bit error insertion in nibble and byte modes?

In nibble and byte modes, the DS2174Q scales error rates: selecting 10⁻¹ produces 8⁻¹, and 10⁻² becomes 8⁻². This occurs because error insertion operates per data word-not per bit-so 4-bit nibble mode yields 1 error per 8 words, and 8-bit byte mode yields 1 per 8 bytes. This behavior is explicitly defined in Table 3-B and Section 3.1.1 of the DS2174Q datasheet.

What is the function of the TCLKO pin on the DS2174Q?

TCLKO (Pin 26) is the gapped transmit clock output, mirroring TCLK but gated by TCLK_EN. When TCLK_EN is low, TCLKO goes inactive (high-impedance or low, depending on CLK_INV setting), enabling precise time-slot control in TDM systems. Its polarity is configurable via CLK_INV bit in Control Register 4 (Address 03h), and its behavior is fully specified in Section 1.7 and Figure 6-3 of the DS2174Q datasheet.