Analog Devices Inc./Maxim Integrated MAX971ESA+T

Overview

The MAX971ESA+T from Maxim Integrated is a single, ultra-low-power, open-drain comparator with integrated 1.182V ±1% voltage reference and programmable hysteresis via HYST pin. It operates from 2.5V to 11V single supply (or ±1.25V to ±5.5V dual supply), draws ≤4µA quiescent current over temperature, supports rail-to-rail input down to V− and within 1.3V of V+, and features separate GND pin for output stage-enabling bipolar-to-single-ended level translation in battery-powered threshold detection systems.

For engineers reviewing the MAX971ESA+T datasheet, MAX971ESA+T pinout, MAX971ESA+T application, or MAX971ESA+T equivalent, key selection criteria include its guaranteed 4µA max supply current across −40°C to +85°C, 1.182V ±1% internal reference accuracy, 12µs propagation delay at 10mV overdrive, open-drain output with 11V output voltage range referenced to GND, and HYST-pin-based hysteresis programming without external feedback.

Technical Context

The MAX971ESA+T implements a micropower comparator core with bandgap-derived 1.182V reference referenced to V−, not GND. Its input common-mode range extends from V− to (V+ − 1.3V), and it uses an N-channel open-drain output transistor with dedicated GND terminal-allowing output sink operation independent of V− when used in single-supply configurations.

Hysteresis is implemented via the HYST pin, accepting voltage between REF and (REF − 50mV); connecting two external resistors between REF–HYST–V− sets symmetric upper/lower thresholds. The device does not support complementary outputs or push-pull drive-only open-drain sinking to GND.

Key Specifications

Pinout & Package

MAX971ESA+T is housed in an 8-pin SO (Small Outline) package, pin-compatible with industry-standard SOIC-8 footprint (JEDEC MS-012). Pin 1 = OUT, Pin 2 = V−, Pin 3 = IN+, Pin 4 = IN−, Pin 5 = HYST, Pin 6 = REF, Pin 7 = V+, Pin 8 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX921ESA+, the MAX971ESA+T reduces component count and layout risk via HYST-pin hysteresis; compared with TLV3701IDBVR, it trades 2.8µA higher typical I_Q for integrated 1.182V ±1% reference and simplified threshold-setting-making it optimal for self-contained, low-component-count detection nodes.

Availability

MAX971ESA+T is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, window comparators, and level translators requiring stable component supply with extended temperature support (−40°C to +85°C).

Supply support for MAX971ESA+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 power, sensing, interface, and reliability-critical applications.

The MAX971ESA+T belongs to the MAX97x/MAX98x micropower comparator family, engineered specifically for ultra-low-power, single-supply threshold detection and level translation in portable and energy-constrained systems.

FAQ

What is the maximum supply voltage for MAX971ESA+T?

The MAX971ESA+T supports a single-supply voltage range of 2.5V to 11V, or dual supplies from ±1.25V to ±5.5V. Absolute maximum ratings allow V+ to V− up to 12V, but functional operation is specified only up to 11V. Exceeding 11V may cause parametric degradation or reliability risk. The MAX971ESA+T must not be operated with total supply voltage exceeding 11V under normal conditions.

Does MAX971ESA+T require an external reference for basic comparator operation?

No, the MAX971ESA+T includes an internal 1.182V ±1% (C-temp) or ±2% (E-temp) bandgap voltage reference accessible at the REF pin. This reference is fully functional and stable across temperature and supply voltage, eliminating the need for external references in most threshold-detection applications. The MAX971ESA+T can operate as a complete, self-contained comparator solution using only its internal reference and HYST pin for hysteresis.

Can MAX971ESA+T drive a 10kΩ pullup resistor reliably at 3.3V supply?

Yes, the MAX971ESA+T open-drain output can sink ≥1.8mA at V_OL ≤ 0.4V (with V+ = 3V, I_OUT = 0.8mA), which comfortably supports a 10kΩ pullup to 3.3V (I_PULLUP = 330µA). Output leakage remains <100nA at 11V, ensuring clean logic-low assertion. The dedicated GND pin maintains sink performance independent of V−, making it robust for level-shifting into 3.3V logic domains.

What is the purpose of the separate GND pin on MAX971ESA+T?

The separate GND pin on the MAX971ESA+T provides a dedicated return path for the output N-channel MOSFET, decoupling output sink behavior from the V− supply rail. This enables true level translation-for example, accepting ±5V inputs while producing 0–3.3V logic outputs-even when V− is connected to −5V. Without this pin, output sinking would be referenced to V−, limiting interoperability across voltage domains. The MAX971ESA+T leverages this architecture for bipolar-to-single-ended conversion.

How is hysteresis programmed on MAX971ESA+T?

Hysteresis on the MAX971ESA+T is programmed using the HYST pin: connect R1 between REF and HYST, and R2 between HYST and V−. The hysteresis band (V_HB) ≈ 2 × (V_REF − V_HYST), with V_HYST adjustable from REF down to (REF − 50mV), yielding up to 100mV total hysteresis. For example, setting V_HYST = REF − 25mV gives ~50mV hysteresis. The MAX971ESA+T datasheet provides exact equations for R1/R2 based on desired V_HB and reference source current limits.