Analog Devices Inc./Maxim Integrated MAX931CPA+

Overview

The MAX931CPA+ 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 up to 40mA, and ultra-low 4µA max supply current over –40°C to +85°C. It operates from +2.5V to +11V single supply (or ±1.25V to ±5.5V dual supply), with input common-mode range extending from V– to V+ – 1.3V - ideal for battery-powered threshold detection in portable instrumentation.

For engineers reviewing the MAX931CPA+ datasheet, MAX931CPA+ pinout, MAX931CPA+ application, or MAX931CPA+ equivalent, key selection considerations include its rail-to-rail input capability down to V–, internal reference accuracy and temperature drift, hysteresis programming method using two external resistors, and output stage immunity to crowbar current during transitions.

Technical Context

The MAX931CPA+ 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 stage that accepts signals from V– to within 1.3V of V+, supporting direct sensing in single-supply systems where ground-referenced references are impractical.

The output stage continuously sources up to 40mA while sinking ≥5mA, with no crowbar current during logic transitions - eliminating supply-line glitches and parasitic feedback. Hysteresis is implemented via the HYST pin, accepting 1.132V to 1.182V (REF – 50mV to REF) to set symmetric thresholds without external feedback networks.

Key Specifications

Pinout & Package

MAX931CPA+ uses an 8-pin plastic DIP package with 0°C to +70°C commercial temperature range. Pin functions are validated per Maxim's official pinout diagram and ordering information table.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX921CPA+, the MAX931CPA+ trades ±1% reference accuracy for lower cost and sufficient precision in most portable threshold applications; versus TLV3011IDBVR, it delivers higher drive strength and eliminates external reference design complexity at the cost of slightly higher quiescent current.

Availability

MAX931CPA+ 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 lifecycle support.

Supply support for MAX931CPA+ 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, automotive, and communications markets.

The MAX931CPA+ belongs to the MAX931–MAX934 micropower comparator family, engineered specifically for ultra-low-power, single-supply threshold detection with integrated reference - targeting portable instrumentation and energy-constrained edge devices.

FAQ

What is the operating temperature range for the MAX931CPA+?

The MAX931CPA+ is specified for the commercial temperature range of 0°C to +70°C, as confirmed in Maxim's official ordering information table. This distinguishes it from the MAX931EPA+ (–40°C to +85°C) variant. The device's 4µA max supply current and 1.182V ±2% reference performance are guaranteed across this full 0°C to +70°C range, making it suitable for indoor consumer and industrial control applications without extended thermal requirements.

Does the MAX931CPA+ require external bypass capacitors?

No, the MAX931CPA+ does not require power-supply bypass capacitors under low-impedance supply conditions, as stated in the "Board Layout and Bypassing" section of the datasheet. However, a 100nF ceramic capacitor is recommended when supply impedance is high or supply leads are long. Critically, the REF pin must never be bypassed - doing so degrades reference stability and increases noise, as the internal bandgap reference is optimized for direct connection to load.

How is hysteresis programmed on the MAX931CPA+?

Hysteresis on the MAX931CPA+ is programmed using the HYST pin with two external resistors: R1 between REF and HYST, and R2 between HYST and V– (GND in single-supply mode). The HYST pin accepts voltages from REF – 50mV to REF, producing a hysteresis band (VHB) ≈ 2 × (REF – VHYST). For example, setting VHYST = REF – 25mV yields ~50mV hysteresis. This method avoids external positive-feedback networks and associated stability issues.

Can the MAX931CPA+ operate from a 3V supply?

Yes, the MAX931CPA+ is fully specified for operation from +2.5V to +11V single supply, including +3V. Electrical characteristics tables explicitly list 3V operation data: supply current is 2.4µA to 3.0µA (typ/max), input offset voltage remains ±10mV, and propagation delay is 14µs at 10mV overdrive. The internal reference remains functional down to ~2.2V, though comparator performance degrades below 2.5V - so 3V is well within reliable operating range.

Is the MAX931CPA+ pin-compatible with any 1% reference comparators?

Yes, the MAX931CPA+ is pin-compatible with the MAX921CPA+, 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 direct substitution where higher reference accuracy is needed, with identical PCB layout, connections, and外围 circuitry - only the reference tolerance changes from ±2% to ±1%.