Analog Devices Inc./Maxim Integrated MAX971ESA+

Overview

The MAX971ESA+ from Maxim Integrated is a single, ultra-low-power, open-drain comparator with integrated 1.182V ±1% precision voltage reference and programmable hysteresis via HYST pin. It operates from a single 2.5V–11V supply (or ±1.25V–±5.5V dual supply), draws ≤4µA quiescent current over –40°C to +85°C, and supports rail-to-rail input voltage range down to V− and up to V+ − 1.3V - ideal for battery-powered threshold detection in portable instrumentation.

For engineers reviewing the MAX971ESA+ datasheet, MAX971ESA+ pinout, MAX971ESA+ application, or MAX971ESA+ equivalent, key selection criteria include its guaranteed ±1% reference accuracy, separate GND pin enabling bipolar-to-single-ended level translation, 12µs propagation delay at 10mV overdrive, and compatibility with 8-pin SO package for space-constrained PCB layouts.

Technical Context

The MAX971ESA+ integrates a micropower bandgap reference (1.182V ±1% over 0°C to +70°C, ±2% over –40°C to +85°C) and a single comparator with open-drain output sinking to GND - distinct from MAX972/MAX973 variants that sink to V−. Its HYST pin enables hysteresis programming using two external resistors without feedback loops or complex calculations.

Input common-mode range extends from V− to V+ − 1.3V; output voltage swing reaches up to 11V above V−, supporting level-shifting applications even with no active V+ supply. Propagation delay is specified at 12µs (high-to-low) under 10mV overdrive with 100pF load and 1MΩ pullup, and input offset voltage is ±10mV max over temperature.

Key Specifications

Pinout & Package

MAX971ESA+ uses an 8-pin SO (Small Outline) package per JEDEC MS-012, with gull-wing leads and 1.27mm pitch. Pin 1 is marked by notch or dot; device orientation follows standard SOIC top-view convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX971ESA+, MAX971CSA offers identical performance at lower cost but lacks extended temperature qualification, while MAX981ESA+ trades ±1% reference accuracy for reduced unit price - making MAX971ESA+ optimal for precision-critical, wide-temperature industrial designs.

Availability

MAX971ESA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, level translators, and window comparators requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX971ESA+ 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 semiconductor company specializing in high-performance analog and mixed-signal ICs for power, sensing, and interface applications.

The MAX971ESA+ belongs to Maxim's ultra-low-power comparator family designed specifically for energy-constrained applications such as portable medical devices, remote sensors, and battery-backed industrial controllers.

FAQ

What is the maximum supply voltage for MAX971ESA+ in single-supply operation?

The MAX971ESA+ supports a single-supply voltage range of 2.5V to 11V. At 11V, the device remains fully functional with guaranteed performance including input common-mode range up to V+ − 1.3V and output voltage capability up to 11V above V−. Exceeding 11V risks permanent damage per Absolute Maximum Ratings.

Does MAX971ESA+ require an external bypass capacitor on the REF pin?

No, the MAX971ESA+ datasheet explicitly states "Do not bypass the REF output." The internal 1.182V reference is optimized for direct connection to the HYST pin or external resistor dividers. Adding capacitance to REF can destabilize the reference and increase noise - verified in Typical Operating Characteristics Figure TOC2.

Can MAX971ESA+ operate with V− floating above GND in dual-supply mode?

Yes - in dual-supply configuration (e.g., V+ = +5V, V− = –5V), the MAX971ESA+ output sinks to Pin 1 (GND), not V−. This allows V− to float at any potential while maintaining clean logic-level output referenced to system ground, enabling true bipolar-to-single-ended conversion without level-shifting circuitry.

What is the guaranteed hysteresis bandwidth achievable with the HYST pin on MAX971ESA+?

The HYST pin on MAX971ESA+ accepts voltages from (REF − 50mV) to REF, producing a maximum hysteresis band (VHB) of 100mV. This is derived from VHB ≈ 2 × (REF − VHYST), with REF = 1.182V ±2% over –40°C to +85°C - confirmed in Applications Information section and Figure 2.

How does the output leakage current of MAX971ESA+ affect high-impedance pull-up networks?

MAX971ESA+ specifies output leakage current ≤100nA at VOUT = 11V. In a 1MΩ pullup to 5V, this contributes ≤100mV error - acceptable for most digital interfaces. For sub-10mV accuracy, use ≤100kΩ pullup or add a buffer; leakage is validated in Electrical Characteristics Table under "Output Leakage Current".