Analog Devices Inc./Maxim Integrated MAX9691EPA

Overview

The MAX9691EPA 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 supplies. It features differential ECL-compatible inputs, complementary open-emitter outputs requiring external 50Ω–200Ω pull-down resistors to –2.0V or –5.2V, and operates across –40°C to +85°C in an 8-pin PDIP package. It enables high-speed line reception and threshold detection in RF instrumentation and test equipment.

For engineers reviewing the MAX9691EPA datasheet, MAX9691EPA pinout, MAX9691EPA application, or MAX9691EPA equivalent, key selection criteria include propagation delay skew (100ps), dispersion (150ps), latch-enable compatibility (not implemented in MAX9691), ECL-level output drive capability, and PDIP package thermal dissipation (727.3mW at +70°C).

Technical Context

The MAX9691EPA implements a BiCMOS-based high-gain, wide-bandwidth comparator core optimized for sub-2ns propagation with minimal delay mismatch between Q and Q̅ outputs. Its input stage maintains DC matching (±11.5mV V_OS) while supporting common-mode range from –2.5V to +3.0V and differential input clamp at 1.7V.

Output stages are open-emitter ECL structures rated for continuous 50mA sink current and compatible with 50Ω transmission-line termination to VT = –2V. The device lacks latch-enable functionality-confirmed by selector guide and pin description-distinguishing it from MAX9692/MAX9693 variants and requiring LE pins to be grounded per design guidelines.

Key Specifications

Pinout & Package

MAX9691EPA uses an 8-pin plastic dual in-line package (PDIP) with standard through-hole mounting and 0.3-inch body width. Pin 1 is VCC, pin 4 is VEE, pins 2 and 3 are IN+ and IN–, pins 5 and 6 are Q OUT and Q OUT, and pins 7 and 8 are GND1 and GND2-separate grounds for input and output stages to minimize coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-fast ECL comparator applications.

Compared with MAX9691EUA, MAX9691EPA offers higher thermal mass and easier hand-soldering but larger board area; versus MAX9692EPE, it trades latch-enable capability for simpler routing and lower cost in fixed-threshold applications.

Availability

MAX9691EPA is available at Aetrix Electronics and suitable for high-speed line receivers, peak detectors, threshold detectors, high-speed triggers, and RF instrumentation requiring stable component supply across industrial temperature ranges.

Supply support for MAX9691EPA 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, mixed-signal, and high-speed ICs for demanding industrial, communications, and computing applications.

The MAX9691EPA belongs to Maxim's ultra-fast comparator product line, engineered specifically for sub-2ns timing-critical applications including RF test equipment, high-speed data acquisition, and optical receiver front-ends.

FAQ

What is the maximum operating frequency supported by the MAX9691EPA?

The MAX9691EPA supports signal processing at frequencies exceeding 600MHz, as confirmed by its 1.2ns typical propagation delay and verified in application circuits using 50Ω-terminated microstrip layouts. This performance is achievable under specified conditions: VCC = +5V, VEE = –5.2V, RL = 50Ω to VT = –2V, and proper high-frequency PCB layout with ground plane and local decoupling. The MAX9691EPA itself does not define a "maximum frequency" as a clocked device, but its propagation characteristics enable reliable operation in >600MHz analog signal paths.

Does the MAX9691EPA include a latch-enable function?

No, the MAX9691EPA does not include a latch-enable function. Per the Selector Guide and Pin Description, only MAX9692 and MAX9693 variants feature LE inputs; the MAX9691EPA has no LE pin and its pinout omits latch-enable terminals. If used in a design derived from MAX9692/MAX9693 schematics, the LE-related pins on MAX9691EPA must be grounded (for unused LE) or tied to appropriate ECL logic levels per datasheet guidance-but the MAX9691EPA itself cannot perform latched comparison.

What external components are required for proper operation of the MAX9691EPA?

The MAX9691EPA requires two critical external components: (1) 0.1µF ceramic bypass capacitors placed as close as possible to VCC (Pin 1) and VEE (Pin 4) pins to suppress supply noise, and (2) external pull-down resistors (50Ω–200Ω to –2.0V, or 240Ω–2000Ω to –5.2V) on Q OUT (Pin 5) and Q OUT (Pin 6) to establish valid ECL logic levels. GND1 (Pin 7) and GND2 (Pin 8) must connect to a solid copper ground plane, and microstrip routing is recommended for output traces to maintain 50Ω impedance.

How does the MAX9691EPA handle input signals outside its common-mode range?

The MAX9691EPA will not false trip if one input remains within the valid common-mode range (–2.5V to +3.0V) while the other input goes outside that range. This behavior is explicitly guaranteed in the Applications Information section and ensures robust operation in noisy or asymmetric signal environments. However, differential input voltage must remain within ±5V, and input clamp voltage is limited to 1.7V-exceeding these limits risks damage. The MAX9691EPA's input stage is designed to tolerate such asymmetry without erroneous output transitions.

What is the thermal performance difference between MAX9691EPA and MAX9691EUA packages?

The MAX9691EPA (8-PDIP) has a power dissipation rating of 727.3mW at +70°C with a derating factor of 9.1mW/°C above +70°C, whereas the MAX9691EUA (8-µMAX) is rated for 387.8mW at +70°C with 4.8mW/°C derating. Although the µMAX package offers superior power density and smaller footprint, the PDIP version provides higher absolute power handling and greater thermal mass-making MAX9691EPA preferable in high-ambient-temperature industrial applications where sustained dissipation exceeds 300mW. Both packages share identical electrical specifications.