Analog Devices Inc./Maxim Integrated MAX931CSA+

Overview

The MAX931CSA+ from Maxim Integrated is a single micropower comparator with integrated 1.182V ±2% bandgap reference, programmable hysteresis via HYST pin, TTL/CMOS-compatible output sinking and sourcing capability, and ultra-low 4µA max supply current over temperature. It operates from +2.5V to +11V single supply (or ±1.25V to ±5.5V dual supply), supports rail-to-rail input down to V− and within 1.3V of V+, and is widely used in battery-powered threshold detection circuits.

For engineers reviewing the MAX931CSA+ datasheet, MAX931CSA+ pinout, MAX931CSA+ application, or MAX931CSA+ equivalent, key selection considerations include its guaranteed 0°C to +70°C commercial temperature range, 8-pin plastic DIP package, internal reference accuracy, hysteresis programming method, and compatibility with low-noise, low-power analog monitoring systems requiring stable trip points.

Technical Context

The MAX931CSA+ integrates a precision 1.182V ±2% reference referenced to V− (not GND), enabling self-contained threshold generation without external components. Its comparator features an input common-mode range extending from V− to (V+ − 1.3V) and eliminates crowbar current during transitions-reducing parasitic supply feedback and improving layout robustness.

The HYST pin allows hysteresis adjustment using two resistors (REF→HYST→V−), delivering up to ±50mV offset at HYST for ~100mV total hysteresis band. Output stage continuously sources up to 40mA and sinks ≥5mA while maintaining sub-4µA quiescent current, making it suitable for direct LED driving or logic-level translation without buffering.

Key Specifications

Pinout & Package

MAX931CSA+ uses an 8-pin plastic DIP package with 0°C to +70°C commercial temperature range. Pin functions are validated per Maxim's official datasheet revision 1 (19-0194).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX931CSA+, MAX921CSA+ offers tighter reference tolerance but higher cost, while TLV3011IDBVR reduces quiescent current significantly but adds design complexity and external component dependency-making MAX931CSA+ optimal for cost-sensitive, self-contained threshold detection.

Availability

MAX931CSA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, oscillator circuits, and alarm circuits requiring stable component supply with long-term manufacturability.

Supply support for MAX931CSA+ 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, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.

The MAX931CSA+ belongs to the MAX93x micropower comparator family, designed specifically for ultra-low-power, self-contained voltage monitoring in portable and energy-constrained systems.

FAQ

What is the operating temperature range for the MAX931CSA+?

The MAX931CSA+ is specified for the commercial temperature range of 0°C to +70°C. This is confirmed in the Ordering Information table and Absolute Maximum Ratings section of the official datasheet. The 'C' suffix in MAX931CSA+ explicitly denotes the commercial grade. For extended temperature operation (–40°C to +85°C), the MAX931ESA+ or MAX931EPA+ variants must be selected instead of the MAX931CSA+.

Does the MAX931CSA+ require external bypass capacitors?

The MAX931CSA+ does not require REF bypassing and recommends against it, as stated in the Applications Information section. Power-supply bypassing is optional: 100nF capacitors are advised only when supply impedance is high or leads are long; low-impedance supplies do not need them. This simplifies layout and reduces BOM count compared to many comparators requiring mandatory decoupling.

Can the MAX931CSA+ operate from a 3V supply?

Yes, the MAX931CSA+ operates from +2.5V to +11V single supply, including 3V. Electrical Characteristics tables explicitly list performance data at V+ = 3V, confirming functionality. Input common-mode range remains V− to (V+ − 1.3V), so at 3V supply, usable input span is 0V to 1.7V - sufficient for many low-voltage sensing tasks.

How is hysteresis implemented on the MAX931CSA+?

Hysteresis on the MAX931CSA+ is implemented using the HYST pin: connect R1 between REF and HYST, and R2 between HYST and V−. This creates a voltage divider that shifts the effective threshold. The HYST pin accepts voltages from REF down to (REF − 50mV), yielding up to ~100mV hysteresis band. No external feedback around the comparator is needed - eliminating stability risks and simplifying design versus traditional methods.

Is the MAX931CSA+ pin-compatible with any other Maxim comparators?

Yes, the MAX931CSA+ is pin-compatible with the MAX921CSA+ (1% reference version), as explicitly stated in the datasheet: "The MAX931, MAX933, and MAX934 are pin-compatible with the 1% accurate MAX921, MAX923, and MAX924, respectively." This allows drop-in replacement where higher reference accuracy is required without PCB redesign.