Analog Devices Inc./Maxim Integrated MAX9427EHJ

Overview

MAX9427EHJ from Maxim Integrated is a quad PECL-to-ECL differential translator IC designed for high-speed clock and data distribution in backplane and base station systems. It features 100Ω integrated differential input termination, 50Ω series output termination, 0.24ps(RMS) added random jitter, <90ps channel-to-channel skew in asynchronous mode, and guaranteed 600mV differential output swing at 3GHz clock frequency.

For engineers reviewing the MAX9427EHJ datasheet, MAX9427EHJ pinout, MAX9427EHJ application, or MAX9427EHJ equivalent, this device is selected for ultra-low-jitter timing integrity in synchronous clock fanout, DSLAM backplane buffering, and ATE signal conditioning where deterministic skew and sub-100ps propagation delay variation are critical.

Technical Context

The MAX9427EHJ implements four independent bipolar PECL-to-ECL translation channels with dual-mode operation: asynchronous (SEL = high) enables per-channel data translation with 420ps typical propagation delay, while synchronous (SEL = low) aligns all outputs to the rising edge of a differential clock with 10ps typical channel-to-channel skew. Input signals are referenced to VCC, outputs to VGG, and both supplies operate independently across ±2.375V to ±5.5V.

Its integrated 100Ω differential input termination eliminates external biasing for PECL sources, and internal 50Ω series output resistors with 8mA pulldown current sources enable direct connection to 50Ω transmission lines terminated to VGG − 2.0V - no external termination components required. Jitter performance is characterized up to 3.0GHz clock and 2.0GHz data rates under full temperature range (−40°C to +85°C).

Key Specifications

Pinout & Package

MAX9427EHJ is housed in a 32-pin 5mm × 5mm TQFP package with exposed thermal pad (pin 11, 17, 24, 30 = VGG; pins 14, 20, 21, 27 = VEE). Corner pins are internally connected to VGG for enhanced grounding and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad PECL-to-ECL translation applications.

Compared with MAX9425EHJ and MAX9426EHJ, the MAX9427EHJ uniquely combines both integrated 100Ω input and 50Ω output termination - reducing component count and layout sensitivity while delivering the lowest jitter and tightest skew in the family for fixed-impedance high-speed backplanes.

Availability

MAX9427EHJ is available at Aetrix Electronics and suitable for central office clock distribution, DSLAM backplane buffering, and 5G base station transceiver clocking requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for MAX9427EHJ 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 high-performance analog, mixed-signal, and power management ICs for precision timing, communications, and industrial applications.

The MAX9424–MAX9427 product line was designed specifically for ultra-low-jitter, low-skew differential translation in telecom infrastructure clock trees and high-speed test equipment where deterministic timing behavior is non-negotiable.

FAQ

What is the maximum clock frequency supported by MAX9427EHJ in synchronous mode?

The MAX9427EHJ supports a maximum clock frequency of 3.0GHz in synchronous mode (SEL = low), with guaranteed 600mV differential output swing and 10ps typical channel-to-channel skew. This specification is validated across the full −40°C to +85°C operating temperature range and applies when VOH − VOL ≥ 500mV. Performance remains stable under worst-case supply conditions (VCC − VGG = 2.375V, VGG − VEE = 2.375V).

Does MAX9427EHJ require external termination resistors on its inputs or outputs?

No, the MAX9427EHJ does not require external termination resistors: it integrates 100Ω differential input termination between each IN_/IN_ pair and 50Ω series output termination on each OUT_/OUT_ pair. These built-in terminations eliminate the need for external resistors, simplifying layout and improving impedance matching for PECL-to-ECL translation at frequencies up to 3.0GHz.

How does the SEL pin control operation mode in MAX9427EHJ?

In MAX9427EHJ, the differential SEL/SEL inputs determine operational mode: when SEL = high and SEL = low, all four channels operate asynchronously (independent data translation); when SEL = low and SEL = high, all channels operate synchronously, clocking outputs on the rising edge of the differential CLK/CLK input. Unused clock inputs must be properly biased in asynchronous mode to prevent noise coupling.

What are the supply voltage requirements for MAX9427EHJ?

The MAX9427EHJ requires three independent supply connections: VCC (+2.375V to +5.5V relative to VGG), VEE (−2.375V to −5.5V relative to VGG), and VGG (ground reference). VCC powers the PECL input stage and is referenced to VGG; VEE powers the ECL output stage. Supplies need not be symmetrical - e.g., +3.3V/VGG/−3.3V or +5.0V/VGG/−2.5V are both valid configurations.

Can MAX9427EHJ drive 50Ω transmission lines directly without additional components?

Yes, MAX9427EHJ can drive 50Ω transmission lines directly: its integrated 50Ω series output termination and 8mA internal pulldown current source are designed to interface with standard 50Ω PCB traces terminated to VGG − 2.0V. This configuration eliminates external resistors and maintains optimal signal integrity up to 3.0GHz, as confirmed by AC electrical characterization in the official datasheet.