Analog Devices Inc./Maxim Integrated MAX972ESA

Overview

The MAX972ESA from Maxim Integrated is a single, ultra-low-power, open-drain comparator with no internal voltage reference and no programmable hysteresis, housed in an 8-pin SO package. It operates from a single 2.5V to 11V supply (or ±1.25V to ±5.5V dual supplies), draws ≤4µA supply current over temperature, supports rail-to-rail input common-mode range (V− to V+ − 1.3V), and features 12µs propagation delay at 10mV overdrive - ideal for battery-powered threshold detection in portable instrumentation.

For engineers reviewing the MAX972ESA datasheet, MAX972ESA pinout, MAX972ESA application, or MAX972ESA equivalent, key selection considerations include its lack of internal reference (requiring external reference or resistor-divider biasing), absence of HYST pin (necessitating external positive-feedback hysteresis), SO-8 packaging, extended temperature range (−40°C to +85°C), and compatibility with single/dual-supply level-shifting topologies.

Technical Context

The MAX972ESA implements a micropower comparator core without integrated reference or hysteresis circuitry, distinguishing it from family members like MAX971 or MAX982. Its input stage accepts voltages from V− to (V+ − 1.3V), enabling operation near supply rails, and its open-drain output sinks current to V− (not GND), requiring an external pullup for logic-level translation.

Unlike MAX971/MAX982, the MAX972ESA lacks REF and HYST pins - eliminating internal 1.182V reference sourcing/sinking and dedicated hysteresis programming. Hysteresis must be implemented externally via feedback resistors, increasing design complexity but preserving full flexibility in threshold setting and noise margin tuning.

Key Specifications

Pinout & Package

Package: 8-pin SO (SOIC-N, 150-mil width), RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar comparator applications.

Compared with MAX972ESA, MAX971ESA adds integrated reference and hysteresis control at the cost of less flexible threshold design, while TLV3701IDBVR offers lower quiescent current and smaller package but lacks V−-referenced sinking - critical for true bipolar-to-single-ended conversion.

Availability

MAX972ESA is available at Aetrix Electronics and suitable for battery-powered systems, power-good monitoring, window detection, and level-shifting applications requiring stable component supply across industrial temperature ranges.

Supply support for MAX972ESA 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 power, sensing, and interface applications in industrial, medical, and communications systems.

The MAX97x/MAX98x comparator family targets ultra-low-power, open-drain threshold detection in resource-constrained environments - emphasizing micropower operation, wide supply range, and robust input/output voltage handling over speed or precision.

FAQ

Does the MAX972ESA include an internal voltage reference?

No, the MAX972ESA does not include an internal voltage reference. Unlike MAX971ESA or MAX982ESA, it lacks a REF pin and associated 1.182V bandgap circuitry. Users must provide an external reference or resistor-divider network to establish the comparison threshold for the MAX972ESA. This design choice reduces quiescent current and increases flexibility in threshold selection.

What is the output sink configuration of the MAX972ESA?

The MAX972ESA output is an open-drain N-channel MOSFET that sinks current to V−, not GND. When V− is tied to system ground (single-supply mode), the output behaves as a standard open-drain stage. In dual-supply configurations (e.g., ±5V), the output sinks to the negative rail, enabling true bipolar-to-single-ended conversion - a key distinction from GND-referenced comparators like TLV3701.

Can the MAX972ESA operate from a 1.8V supply?

No, the MAX972ESA has a guaranteed minimum single-supply voltage of 2.5V. Operation below this level is not specified and results in degraded performance: reference functionality ceases below ~2.2V (though irrelevant here, as MAX972ESA has no reference), propagation delay increases significantly, and output sink current drops. For 1.8V systems, consider alternatives such as TLV3701IDBVR or TSV631ILT.

How is hysteresis implemented on the MAX972ESA?

Hysteresis for the MAX972ESA must be implemented externally using positive feedback, as the device lacks a HYST pin. A resistor network connects the output to the noninverting input (IN+) to create regenerative feedback. The hysteresis width depends on the ratio of feedback and input resistors. Careful layout is required to avoid oscillation, especially with high-impedance dividers driving IN+ or IN−.

What is the maximum output voltage the MAX972ESA can tolerate?

The MAX972ESA output can withstand up to 11V above V−, regardless of whether V+ is powered. This allows the device to function as a level translator even when the main supply is off - for example, pulling a 5V bus line low while operating from a separate 3.3V rail. Absolute maximum rating is VOUT = (V− − 0.3V) to (V− + 12V), with continuous short-circuit capability.