Analog Devices Inc./Maxim Integrated MAX973CUA+

Overview

The MAX973CUA+ from Maxim Integrated is a dual ultra-low-power open-drain comparator with integrated 1.182V ±1% voltage reference and programmable hysteresis via HYST pin. It operates from single 2.5V–11V or dual ±1.25V–±5.5V supplies, draws ≤4µA supply current over temperature, supports rail-to-rail input (V− to V+ −1.3V), and features separate GND for output stage - enabling bipolar-to-single-ended level translation in battery-powered threshold detection systems.

For engineers reviewing the MAX973CUA+ datasheet, MAX973CUA+ pinout, MAX973CUA+ application, or MAX973CUA+ equivalent, key selection criteria include its dual-comparator architecture with internal reference, 12µs propagation delay at 10mV overdrive, 8-pin µMAX package footprint, and compatibility with low-voltage (≥2.5V) single-supply operation in space-constrained portable instrumentation.

Technical Context

The MAX973CUA+ integrates two independent comparators sharing one precision 1.182V ±1% bandgap reference and a dedicated HYST pin for resistor-programmable hysteresis without external feedback. Its input common-mode range extends from V− to V+ −1.3V, and inputs tolerate ±0.3V beyond rails without damage.

Output stages are open-drain N-channel MOSFETs sinking to V− (not GND), supporting wire-OR configurations and level-shifting up to 11V output swing. Propagation delay is 12µs (high-to-low) at 10mV overdrive with 100pF load and 1MΩ pullup; low-to-high response depends on RC time constant and is not internally accelerated.

Key Specifications

Pinout & Package

Package: 8-pin µMAX (3mm × 3mm, 0.5mm pitch), thermally enhanced exposed pad, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX973CUA+, MAX983CUA+ offers identical form-factor and hysteresis capability at lower reference accuracy, while TLV3702IDR trades micropower operation and integrated reference for broader supply range and output drive strength - making MAX973CUA+ optimal for space- and energy-constrained dual-threshold detection.

Availability

MAX973CUA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, and level translators requiring stable component supply across industrial temperature grades and long-lifecycle production programs.

Supply support for MAX973CUA+ 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 management, sensing, and signal conditioning in demanding environments.

The MAX97x/MAX98x comparator family was engineered for ultra-low-power, single/dual-supply threshold detection with integrated reference - targeting portable instrumentation, energy-harvesting nodes, and fail-safe power monitoring where size, current, and component count are critical.

FAQ

What is the maximum supply voltage for MAX973CUA+ in single-supply operation?

The MAX973CUA+ supports a single-supply voltage range of 2.5V to 11V. When operated in single-supply mode, V− is connected to GND, and the total supply voltage (V+ − V−) must not exceed 11V. Absolute maximum ratings allow V+ to reach 12V relative to V−, but functional operation is guaranteed only up to 11V per datasheet specifications. Exceeding 11V may compromise reference stability and comparator accuracy in the MAX973CUA+.

Can MAX973CUA+ operate from a 3V supply while maintaining full specification?

Yes, the MAX973CUA+ is fully specified at 3V single supply (V+ = 3V, V− = GND). At this voltage, supply current remains ≤4µA, input common-mode range covers 0V to 1.7V, propagation delay is 12µs (high-to-low), and reference output holds 1.182V ±1%. The device meets all electrical characteristics in the Commercial temperature range (0°C to +70°C) at 3V, making it suitable for modern low-voltage portable designs where the MAX973CUA+ delivers consistent performance without derating.

Does MAX973CUA+ require an external bypass capacitor on the REF pin?

No, the MAX973CUA+ datasheet explicitly states "Do not bypass the REF output." The internal 1.182V reference is optimized for direct connection to resistor dividers or HYST networks. Adding capacitance to REF can destabilize the bandgap core and increase noise, degrading hysteresis accuracy and threshold repeatability. For clean operation, route REF with short traces, avoid coupling to noisy nodes, and rely on the MAX973CUA+'s inherent reference regulation rather than external filtering.

How is hysteresis programmed on MAX973CUA+?

Hysteresis on the MAX973CUA+ is programmed by connecting two resistors between REF, HYST, and V−. R1 connects REF to HYST; R2 connects HYST to V−. The hysteresis band (VHB) ≈ 2 × (VREF − VHYST), with VHYST adjustable from REF down to REF −50mV - yielding up to 100mV total hysteresis. This method replaces external positive-feedback networks, avoids oscillation risks, and consumes negligible current. The MAX973CUA+ applies identical hysteresis to both comparators, simplifying window detector design.

What is the output stage configuration of MAX973CUA+ and how does it affect interfacing?

The MAX973CUA+ features open-drain N-channel MOSFET outputs (OUTA and OUTB) that sink current to V−, not GND. This configuration enables wire-ORing of multiple comparators and level translation across different supply domains (e.g., ±5V input to 3.3V logic). To interface, each output requires an external pullup resistor to the desired logic rail. The output voltage swing reaches up to 11V above V−, allowing robust signaling even when V+ is unpowered - a key advantage in fault-tolerant systems using the MAX973CUA+.