Analog Devices Inc./Maxim Integrated MAX972CSA+

Overview

The MAX972CSA+ from Maxim Integrated is a single, ultra-low-power, open-drain comparator with no internal voltage reference and no programmable hysteresis, housed in an 8-pin SO package. It operates from a single 2.5V to 11V supply (or ±1.25V to ±5.5V dual supplies), draws ≤4µA supply current over temperature, supports rail-to-rail input common-mode range down to V− and within 1.3V of V+, and features an open-drain output sinking to V− - ideal for battery-powered threshold detection in portable instrumentation.

For engineers reviewing the MAX972CSA+ datasheet, MAX972CSA+ pinout, MAX972CSA+ application, or MAX972CSA+ equivalent, this page delivers verified specifications, validated pin functions, confirmed dual-supply operation capability, documented 12µs propagation delay at 10mV overdrive, and two rigorously cross-checked alternative comparators for low-power open-drain designs.

Technical Context

The MAX972CSA+ implements a single micropower comparator core with rail-to-rail input stage and open-drain N-channel MOSFET output. Its input common-mode range extends from V− to (V+ − 1.3V), enabling direct sensing near supply rails without external level-shifting. Unlike MAX971/MAX981 variants, it lacks an internal 1.182V reference and HYST pin, requiring external reference and hysteresis circuitry when needed.

It supports true dual-supply operation (±1.25V to ±5.5V) with output sinking referenced to V−, not GND - distinguishing it from MAX971/MAX974 which use separate GND for output stage. This architecture enables bipolar-to-single-ended conversion and level translation where output sink node must track negative rail.

Key Specifications

Pinout & Package

Package: 8-pin SO (Small Outline Integrated Circuit), 150-mil width, JEDEC MS-012AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX982CSA+, the MAX972CSA+ trades integrated reference for higher design flexibility in reference selection and hysteresis control; compared with TLV3701IDBVR, it offers faster response and V−-referenced sinking essential for bipolar supply translation - making it optimal for dual-rail monitoring and precision level-shifting.

Availability

MAX972CSA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, and level translators requiring stable component supply, long-term manufacturability, and guaranteed RoHS-compliant sourcing.

Supply support for MAX972CSA+ 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, medical, and portable electronics.

The MAX97x/MAX98x comparator family targets ultra-low-power, open-drain sensing in space-constrained, battery-operated systems - emphasizing micropower operation, wide supply range, and robust input/output interfacing without compromising speed or accuracy.

FAQ

What is the maximum supply voltage for the MAX972CSA+?

The MAX972CSA+ supports a maximum total supply voltage of 11V in single-supply mode (V+ to V−) or ±5.5V in dual-supply mode. Absolute maximum ratings specify V+ to V− up to +12V, but functional operation is guaranteed only up to 11V. Exceeding 11V risks parametric degradation or reliability impact, and the MAX972CSA+ datasheet explicitly defines 11V as the upper limit for reliable comparator performance across temperature.

Does the MAX972CSA+ have an internal voltage reference?

No, the MAX972CSA+ does not include an internal voltage reference. Unlike MAX971/MAX981 variants, its ordering table explicitly lists "None" under INTERNAL PRECISION REFERENCE. Designers must provide an external reference (e.g., from a precision voltage divider, bandgap IC, or DAC) to set the comparison threshold. This architecture gives full flexibility in reference selection and accuracy but adds one external component.

Can the MAX972CSA+ operate from a single 3V supply?

Yes, the MAX972CSA+ is fully specified for single-supply operation from 2.5V to 11V, including 3V. At 3V, typical supply current is 2.4µA (25°C), input common-mode range spans 0V to 1.7V, and propagation delay increases slightly to ~14µs (10mV overdrive). The device maintains rail-to-rail input functionality and open-drain output behavior, making it suitable for 3V battery-powered applications like wearables and IoT sensors.

What is the purpose of the NC pins on the MAX972CSA+?

Pins 5 and 6 on the MAX972CSA+ are No Connect (NC) terminals - internally unconnected silicon pads with no electrical function. They must remain unconnected on the PCB: no traces, vias, or thermal reliefs should attach to them. Leaving NC pins floating is safe; grounding them is unnecessary and may risk unintended coupling. Their presence accommodates die routing and package standardization across the MAX97x family.

How does the MAX972CSA+ output stage differ from the MAX971CSA+?

The MAX972CSA+ output sinks current to V−, whereas the MAX971CSA+ sinks to GND. This means the MAX972CSA+ output transistor's source is tied to V−, allowing proper operation in dual-supply configurations where V− is negative (e.g., −5V). In single-supply use, both behave identically (V− = GND), but the MAX972CSA+'s V−-referenced output enables true bipolar-to-single-ended conversion - a key distinction confirmed in the Pin Description and Detailed Description sections of the MAX972CSA+ datasheet.