Analog Devices Inc./Maxim Integrated MAX9691ESA-T

Overview

MAX9691ESA-T from Maxim Integrated is a single-channel, ultra-fast ECL-output comparator with 1.2ns typical propagation delay, ±11.5mV input offset voltage, and dual ±5.2V/+5V supply operation. It features differential inputs, complementary open-emitter outputs compatible with ECL logic levels, and drives 50Ω-terminated transmission lines-used in high-speed line receivers and threshold detection circuits operating beyond 600MHz.

For engineers reviewing the MAX9691ESA-T datasheet, MAX9691ESA-T pinout, MAX9691ESA-T application, or MAX9691ESA-T equivalent, key selection criteria include propagation delay skew (100ps), dispersion (150ps), latch-enable compatibility (not implemented in MAX9691), SO-8 package thermal performance (588.2mW at +70°C), and ECL-level output drive capability requiring external pull-down resistors.

Technical Context

The MAX9691ESA-T employs BiCMOS process technology to achieve sub-2ns propagation delay while maintaining DC matching characteristics typical of slower comparators. Its differential input stage operates over a -2.5V to +3.0V common-mode range, with 60kΩ differential input resistance and 3pF input capacitance-optimized for high-frequency signal integrity.

As an open-emitter ECL comparator, it requires external pull-down resistors (50Ω–200Ω to -2.0V or 240Ω–2000Ω to -5.2V) to establish valid logic levels. The device draws 34–50mA supply current and exhibits 60dB PSRR on both positive and negative rails, supporting stable operation in noisy high-speed environments.

Key Specifications

Pinout & Package

MAX9691ESA-T is housed in an 8-pin SO (Small Outline) package per outline 21-0041, RoHS-compliant with lead-free termination. Pin 1 is VCC; pins 7 and 8 are GND1 and GND2 (separate ground returns for input and output stages); pins 2 and 3 are IN+ and IN−; pins 5 and 6 are Q OUT and Q OUT; pin 4 is VEE.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed ECL comparator applications.

Compared with MAX9691ESA-T, the MAX9691EUA-T offers identical speed and precision in a smaller footprint but reduced thermal capacity, while the LMH7322MA/NOPB trades ECL compatibility and line-driving capability for lower supply voltage and CMOS integration-making each alternative suitable only under specific system-level constraints.

Availability

MAX9691ESA-T is available at Aetrix Electronics and suitable for high-speed line receivers, threshold detectors, peak detectors, and high-speed triggers requiring stable component supply across industrial and test equipment lifecycles.

Supply support for MAX9691ESA-T 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) designs precision analog and mixed-signal ICs for demanding performance applications, with expertise in high-speed, low-noise, and power-efficient solutions.

The MAX9691ESA-T belongs to Maxim's ultra-fast comparator product line, engineered specifically for ECL-level signal conditioning in >600MHz data acquisition, instrumentation, and communications infrastructure.

FAQ

What is the maximum operating frequency supported by the MAX9691ESA-T?

The MAX9691ESA-T supports signal processing at frequencies exceeding 600MHz, validated by its 1.2ns typical propagation delay and <2.0ns worst-case delay across temperature. This performance enables use in high-speed line receivers and triggers where timing resolution below 2ns is required-consistent with ECL-logic timing budgets in telecom and test equipment.

Does the MAX9691ESA-T include a latch-enable function?

No, the MAX9691ESA-T does not implement latch-enable functionality. That feature is exclusive to the MAX9692 and MAX9693 variants. The MAX9691ESA-T is a single comparator without LE pins; its pinout contains only VCC, IN+, IN−, VEE, Q OUT, Q OUT, GND1, and GND2-no latch control terminals are present or functional in this part.

What external components are required for proper operation of the MAX9691ESA-T?

The MAX9691ESA-T requires two 0.1µF ceramic decoupling capacitors-one each from VCC and VEE to ground-and external pull-down resistors on both Q OUT and Q OUT pins. Pull-down values range from 50Ω to 200Ω tied to -2.0V, or 240Ω to 2000Ω tied to -5.2V, to establish valid ECL logic levels per the datasheet's recommended termination scheme.

How does the MAX9691ESA-T handle input common-mode voltage variations?

The MAX9691ESA-T accepts input common-mode voltages from -2.5V to +3.0V, with 60dB common-mode rejection ratio (CMRR) over that range. This wide range supports AC-coupled inputs and DC-biased signals in mixed-voltage systems, while the high CMRR suppresses noise coupled onto differential pairs-critical for maintaining accuracy in noisy high-speed PCB environments.

Is the MAX9691ESA-T pin-compatible with other devices in the MAX969x family?

No, the MAX9691ESA-T is not pin-compatible with MAX9692 or MAX9693 variants. It uses an 8-pin SO package with no latch-enable pins, whereas MAX9692 requires 10-pin µMAX or 16-pin SO packages, and MAX9693 uses 16-pin QSOP/SO with dual-channel and latch-enable pins. Board layout must be dedicated to the MAX9691ESA-T's 8-pin configuration.