Analog Devices Inc./Maxim Integrated MAX978EEE

Overview

The MAX978EEE from Maxim Integrated is a quad, high-speed, low-power comparator optimized for +3V/+5V single-supply operation. It delivers 20ns propagation delay per channel with only 225µA supply current per comparator, features rail-to-rail outputs and ground-sensing inputs (–0.2V to V_CC – 1.2V), and is housed in a 16-pin QSOP package for space-constrained industrial and battery-powered threshold detection systems.

For engineers reviewing the MAX978EEE datasheet, MAX978EEE pinout, MAX978EEE application, or MAX978EEE equivalent, key selection criteria include guaranteed 20ns propagation delay across –40°C to +85°C, internal hysteresis for noise immunity, shutdown capability (via external control on MAX998 only-MAX978 does not support shutdown), and compatibility with CMOS/TTL logic without pull-up resistors.

Technical Context

The MAX978EEE implements four independent high-speed comparators in a single monolithic CMOS IC. Each channel operates from a single 2.7V to 5.5V supply, supports common-mode input voltages down to –0.2V (ground-sensing), and drives rail-to-rail outputs capable of sinking/sourcing 2mA while maintaining VOL ≤ 0.4V and VOH ≥ V_CC – 0.4V.

It integrates internal hysteresis (typ. 1.5mV input-referred) to prevent oscillation during slow input transitions, tolerates continuous short-circuit faults to either rail, and exhibits 66dB CMRR and 63dB PSRR at 5V supply-enabling robust performance in noisy industrial signal conditioning and IR receiver front-ends.

Key Specifications

Pinout & Package

The MAX978EEE is packaged in a 16-pin QSOP (Quad Small Outline Package) with 0.15mm lead pitch and JEDEC MO-137AC footprint. Pin 1 is marked with a dot; pins are numbered counterclockwise from the top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX978EEE, LM339MTX/NOPB trades speed and rail-to-rail drive for cost and legacy compatibility, while TLV3502IDR offers superior speed and quiescent current but sacrifices ground-sensing functionality essential for sensor biasing and negative-offset signal conditioning.

Availability

The MAX978EEE is available at Aetrix Electronics and suitable for battery-powered systems, IR receivers, digital line receivers, and window comparator circuits requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX978EEE 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 U.S.-based semiconductor company specializing in high-performance analog and mixed-signal ICs for industrial, communications, and consumer applications.

The MAX976/MAX978/MAX998 family was designed specifically for single-supply, high-speed comparator applications demanding low power, ground-sensing capability, and rail-to-rail outputs in compact packages.

FAQ

What is the maximum operating supply voltage for the MAX978EEE?

The MAX978EEE has an absolute maximum supply voltage rating of +6V. However, its specified operational range is +2.7V to +5.5V. Operating continuously at 6V may compromise long-term reliability and is outside the guaranteed performance envelope defined in the datasheet. For robust design, maintain V_CC within 2.7V–5.5V, with 0.1µF local decoupling at the V_CC pin. The MAX978EEE is not rated for 6V sustained operation.

Does the MAX978EEE support shutdown mode like the MAX998?

No, the MAX978EEE does not include a shutdown feature. Shutdown functionality is exclusive to the MAX998 (single comparator) variant, which uses the SHDN pin to reduce supply current to 1nA and place the output in high-impedance state. The MAX978EEE is a quad comparator with no dedicated shutdown control; all four channels remain active whenever V_CC is applied. Power savings must be achieved externally via supply gating or system-level sleep modes.

Can the MAX978EEE inputs safely operate below ground?

Yes, the MAX978EEE inputs support a common-mode voltage range extending to –0.2V relative to GND, enabling true ground-sensing operation. This allows direct interface with sensors or signal sources whose outputs swing slightly below ground (e.g., thermocouples, AC-coupled amplifiers). However, the absolute minimum input voltage is –0.3V - exceeding this risks permanent damage. The MAX978EEE maintains correct output logic states as long as at least one input remains within the full common-mode range (–0.2V to V_CC–1.2V).

What is the output drive capability of the MAX978EEE?

The MAX978EEE features rail-to-rail push-pull outputs capable of sourcing and sinking up to 2mA while maintaining VOL ≤ 0.4V and VOH ≥ V_CC–0.4V at 25°C. Its output stage is designed to directly drive CMOS and TTL logic without external pull-up resistors. Short-circuit current is rated at 74mA (min) and 90mA (typ) when sinking to GND or sourcing to V_CC, with continuous fault tolerance - a key reliability feature for industrial I/O protection.

How does internal hysteresis improve noise immunity in the MAX978EEE?

The MAX978EEE incorporates internal hysteresis (0.5mV to 4.0mV, typ. 1.5mV input-referred) that creates distinct upper and lower trip points for each comparator. This prevents output oscillation when input signals hover near the threshold due to noise or slow slew rates. Unlike external hysteresis networks, the internal version requires no additional resistors or layout area, preserves propagation delay consistency, and ensures matched behavior across all four channels - critical for synchronized multi-threshold detection in the MAX978EEE.