Analog Devices Inc./Maxim Integrated MAX972EPA

Overview

The MAX972EPA 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 plastic DIP 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 down to V− and up to V+ − 1.3V, and features an open-drain output sinking to V−. It is used in battery-powered threshold detection where minimal quiescent current and wide supply flexibility are critical.

For engineers reviewing the MAX972EPA datasheet, MAX972EPA pinout, MAX972EPA application, or MAX972EPA equivalent, key selection considerations include its lack of internal reference (requiring external reference or resistor-divider biasing), absence of HYST pin (necessitating external hysteresis via feedback), 12µs propagation delay at 10mV overdrive, −40°C to +85°C extended temperature rating, and compatibility with single- or dual-supply level translation circuits.

Technical Context

The MAX972EPA implements a single micropower comparator core with N-channel open-drain output stage sinking to V− (not GND), distinguishing it from MAX971/MAX974/MAX981/MAX984 variants that feature separate GND pins for output. Its input stage accepts voltages from V− to V+ − 1.3V, enabling direct sensing near supply rails without clamping diodes.

No internal bandgap reference or HYST control pin is integrated-unlike MAX971/MAX982/MAX973-so external reference generation and hysteresis implementation (e.g., via positive feedback) are mandatory. Supply current remains stable across 2.5V–11V operation, with typical values of 2.5µA at 3V and 3.8µA at 5V over the full −40°C to +85°C range.

Key Specifications

Pinout & Package

MAX972EPA is supplied in an 8-pin plastic DIP package (0.300" width), with pin 1 designated as OUTA, pin 2 as V−, pin 3 as INA+, pin 4 as INA−, pin 5 as NC (no connection), pin 6 as NC, pin 7 as V+, and pin 8 as GND. The GND pin connects to system ground and serves as the reference for V+ and V− supply connections in single-supply operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX971EPA, MAX972EPA trades internal reference and hysteresis convenience for lower cost and reduced risk of reference-related drift; versus TLV3701IP, it offers higher output voltage tolerance and dual-supply robustness at the expense of higher quiescent current.

Availability

MAX972EPA is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, level translators, and oscillator circuits requiring stable component supply across industrial temperature ranges.

Supply support for MAX972EPA 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, interface, and timing applications in industrial, automotive, and communications markets.

The MAX97x/MAX98x comparator family targets ultra-low-power, wide-supply, open-drain comparators for battery-critical and rail-flexible applications - emphasizing quiescent current minimization, input range extension, and output versatility over speed or precision.

FAQ

What is the maximum output voltage swing supported by the MAX972EPA?

The MAX972EPA open-drain output supports a maximum voltage swing of 0V to 11V relative to V−. This means the output can be pulled up to any voltage up to 11V above the V− pin, even when V+ is unpowered - making it ideal for level-shifting between isolated supply domains. This specification is guaranteed across the full −40°C to +85°C temperature range and applies regardless of whether the device is operated from single or dual supplies. The MAX972EPA output stage is designed to sink current to V−, not GND, so proper connection of V− is essential for correct operation.

Does the MAX972EPA include an internal voltage reference?

No, the MAX972EPA does not include an internal voltage reference. Unlike MAX971/MAX973/MAX981/MAX982, which integrate a 1.182V ±1% or ±2% bandgap reference, the MAX972EPA omits this function entirely. Users must provide an external reference voltage or use a resistor divider network to set the comparison threshold. This design choice reduces cost and die area while avoiding reference-related drift and noise - but places full responsibility for reference stability and accuracy on the external circuit. The MAX972EPA datasheet explicitly lists "None" under "INTERNAL PRECISION REFERENCE" in the ordering table.

Can the MAX972EPA be used with dual supplies?

Yes, the MAX972EPA supports dual-supply operation from ±1.25V to ±5.5V. In this configuration, V+ connects to the positive rail (e.g., +5V), V− connects to the negative rail (e.g., −5V), and GND connects to system ground. The input common-mode range extends from V− to V+ − 1.3V, allowing valid operation with inputs referenced to either rail. The output sinks to V−, enabling true bipolar-to-single-ended conversion - for example, converting ±5V sensor outputs into a 0–5V logic signal when pulled up to +5V. This capability is confirmed in the "Power Supplies" section of the datasheet and distinguishes MAX972EPA from comparators with GND-referenced outputs.

What is the purpose of the NC pins (pins 5 and 6) on the MAX972EPA?

Pins 5 and 6 on the MAX972EPA are designated as NC (no connection) and must remain unconnected - they have no internal bond wires or circuitry attached. These pins exist due to package pinout compatibility with other members of the MAX97x/MAX98x family (e.g., MAX971 has REF on pin 6, MAX973 has HYST on pin 5), but are intentionally left unused in MAX972EPA to reflect its lack of reference and hysteresis features. Connecting them to any net - including ground, supply, or signal traces - may cause unpredictable behavior or violate absolute maximum ratings. The datasheet's Pin Description table explicitly lists both pins as "-", and the Functional Diagram confirms no internal connectivity.

How does the MAX972EPA's propagation delay vary with supply voltage and overdrive?

The MAX972EPA exhibits a typical propagation delay of 12µs with 10mV input overdrive and a 100pF capacitive load pulled up via 1MΩ to V+. At 100mV overdrive, delay improves to 4µs. Delay increases significantly at low supply voltages: at V+ = 3V, typical delay rises to ~15µs (10mV overdrive), and further degrades below 2.5V. This behavior stems from reduced output drive strength and slower internal node slewing at lower V+. The datasheet's Typical Operating Characteristics (TOC13) quantifies this dependency - confirming that delay is supply- and overdrive-sensitive. Designers must verify timing margins across the full operating voltage and temperature range, especially in battery-powered systems where V+ declines over discharge.