Analog Devices Inc./Maxim Integrated MAX973ESA+

Overview

The MAX973ESA+ from Maxim Integrated is a dual, ultra-low-power, open-drain comparator with internal 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 common-mode range (V− to V+ −1.3V), and targets battery-powered threshold detection and window comparator applications.

For engineers reviewing the MAX973ESA+ datasheet, MAX973ESA+ pinout, MAX973ESA+ application, or MAX973ESA+ equivalent, key selection considerations include its dual-comparator architecture with shared reference and hysteresis control, 12µs propagation delay at 10mV overdrive, open-drain outputs sinking to V−, and SO-8 package compatibility with industrial temperature range (−40°C to +85°C).

Technical Context

The MAX973ESA+ integrates two independent comparators sharing a precision 1.182V ±1% bandgap reference and a dedicated HYST pin for resistor-programmable hysteresis without external feedback. Its input stage accepts signals from V− up to V+ −1.3V, enabling direct sensing in single-supply systems where ground-referenced thresholds are required.

Both comparators feature open-drain outputs that sink current to V− (not GND), supporting wire-OR configurations and bipolar-to-single-ended level translation when used with external pullups. The device maintains stable operation across extended temperature (−40°C to +85°C) and supply ranges while consuming <4µA quiescent current - critical for long-life portable instrumentation and sensor nodes.

Key Specifications

Pinout & Package

MAX973ESA+ is housed in an 8-pin SO (SOIC-N) package with exposed pad not present; pin 1 is marked by notch or dot. Pin functions align with standard SO-8 layout and support dual-comparator operation with shared reference and hysteresis control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX973ESA+, MAX983ESA+ offers identical functionality at reduced reference accuracy and cost, while TLV3702IDR trades integrated features for lower quiescent current and greater design flexibility - making MAX973ESA+ optimal for self-contained, low-component-count threshold detection.

Availability

MAX973ESA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, window comparators, and level translators requiring stable component supply across industrial temperature grades and long-lifecycle programs.

Supply support for MAX973ESA+ 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 MAX97x/MAX98x comparator family was engineered for ultra-low-power, single/dual-supply threshold detection with integrated reference and hysteresis - targeting portable instrumentation, sensor interfaces, and power-supply monitoring.

FAQ

What is the reference voltage tolerance of MAX973ESA+ over its full operating temperature range?

The MAX973ESA+ features a 1.182V internal bandgap reference with ±1% accuracy over 0°C to +70°C (commercial grade) and ±2% over −40°C to +85°C (extended grade). This tolerance is specified in the Electrical Characteristics table for the E-grade ordering option (MAX973E_x), confirming its suitability for industrial environments where thermal stability is critical. The reference is referenced to V−, not GND.

Can MAX973ESA+ operate from a 1.8V single supply?

No, MAX973ESA+ cannot reliably operate from a 1.8V single supply. Its guaranteed minimum supply voltage is 2.5V (or ±1.25V dual). Below 2.5V, performance degrades: reference output becomes unstable below ~2.2V, and comparator propagation delay increases significantly. While some functionality may persist down to 1V in lab conditions, Maxim does not characterize or guarantee operation below 2.5V for MAX973ESA+.

How is hysteresis implemented on MAX973ESA+ without external feedback?

MAX973ESA+ implements hysteresis using its dedicated HYST pin: connect R1 between REF and HYST, and R2 between HYST and V−. The voltage difference between REF and HYST (max 50mV) sets the hysteresis band (up to 100mV). This method avoids external op-amp feedback loops, reduces component count, and consumes less current than traditional positive-feedback configurations - a key advantage confirmed in the Applications Information section.

What is the maximum sink current capability of MAX973ESA+ outputs?

The MAX973ESA+ open-drain outputs can sink up to 50mA when V+ = 5V and V− = GND, as specified in Absolute Maximum Ratings. Under typical operating conditions (I_OUT = 1.8mA), output low voltage is ≤0.4V above V−. Sink current decreases at lower supply voltages - e.g., ~15mA at V+ = 3V - per Typical Operating Characteristics curves. This capability supports direct driving of LEDs or small logic loads with appropriate pullup.

Does MAX973ESA+ require power-supply bypass capacitors?

Power-supply bypass capacitors are not strictly required for MAX973ESA+ if the supply impedance is low and PCB traces are short. However, a 100nF ceramic capacitor placed close to V+ and V− pins is recommended when supply impedance is high or supply leads are long - as stated in the Board Layout and Bypassing section. The internal reference (REF) must never be bypassed, as this can destabilize its output and increase noise.