Analog Devices Inc./Maxim Integrated MAX9120EXK

Overview

MAX9120EXK from Maxim Integrated is a nanopower, open-drain output comparator in SC70-5 package, featuring Beyond-the-Rails™ inputs (VEE − 0.2V to VCC + 0.2V), guaranteed operation down to +1.6V supply, and ultra-low 350nA supply current. It serves as a precision threshold detector in 2-cell battery monitoring systems where rail-to-rail input range and minimal quiescent power are critical.

For engineers reviewing the MAX9120EXK datasheet, MAX9120EXK pinout, MAX9120EXK application, or MAX9120EXK equivalent, this page delivers verified electrical specs, SC70 package layout, real-world use cases in low-voltage sensing, and validated alternative options for mixed-voltage logic-level translation and battery end-of-life detection.

Technical Context

The MAX9120EXK implements an open-drain output stage compatible with pull-up voltages up to +6V (relative to VEE), enabling direct interfacing across voltage domains (e.g., 5V logic driving 3V I/O). Its internal hysteresis band of 4mV ensures clean switching without external components under slow-moving input conditions.

Input bias current is ≤2nA over −40°C to +85°C, and common-mode rejection ratio (CMRR) is 0.5–3mV/V - sufficient for ground-referenced or supply-line sensing where high-precision offset tracking is not required. The device exhibits crowbar-current-free switching, eliminating supply glitches during output transitions.

Key Specifications

Pinout & Package

MAX9120EXK is housed in a 5-pin SC70-5 package (package code X5-1), measuring 2.0mm × 1.25mm × 0.95mm, with 0.65mm lead pitch. Pin 1 is marked by a dot; pin numbering follows standard SC70 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV3691IDCKR and MAX9121EXK-T, the MAX9120EXK uniquely balances ultra-low 350nA current, open-drain flexibility for voltage-domain bridging, and proven reliability in battery-monitoring systems - making it the preferred choice where both power and interface versatility are constrained.

Availability

MAX9120EXK is available at Aetrix Electronics and suitable for 2-cell battery monitoring, ultra-low-power telemetry, and mixed-voltage logic-level translation requiring stable component supply across industrial, medical, and portable electronics programs.

Supply support for MAX9120EXK 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 harsh, space-constrained, and battery-sensitive environments.

The MAX9117–MAX9120 family was engineered specifically for nanopower, rail-to-rail+200mV input comparators in SC70 packaging - targeting long-life battery-operated systems where every nanoamp counts and board area is at a premium.

FAQ

What is the maximum allowable voltage on the MAX9120EXK OUT pin?

The MAX9120EXK OUT pin supports voltages up to +6V relative to VEE (typically GND), per Absolute Maximum Ratings. This allows safe use with pull-up resistors connected to higher-voltage rails (e.g., 5V) while the device itself operates from a lower VCC (e.g., 1.8V). Exceeding +6V risks permanent damage to the output transistor.

Does the MAX9120EXK have an internal voltage reference?

No, the MAX9120EXK does not include an internal voltage reference. It belongs to the "without reference" variant of the MAX9117–MAX9120 family. Reference functionality is exclusive to MAX9117/MAX9118 (which integrate a 1.252V ±1.75% reference). The MAX9120EXK requires an external reference or resistor divider for threshold setting.

Can the MAX9120EXK operate from a 1.6V supply?

Yes, the MAX9120EXK is fully specified and guaranteed to operate from +1.6V to +5.5V supply voltage across −40°C to +85°C. At 1.6V, typical supply current remains 350nA, and input common-mode range extends from −0.2V to +1.8V - enabling direct interface with low-voltage battery stacks.

What is the purpose of the internal hysteresis in the MAX9120EXK?

The MAX9120EXK features a fixed 4mV internal hysteresis band to prevent output oscillation when input signals hover near the threshold voltage. This eliminates the need for external positive-feedback resistors in basic detection applications - simplifying design and improving reliability in noisy or slow-moving analog signals like decaying battery voltage.

How does the MAX9120EXK differ from the MAX9121EXK-T?

The MAX9120EXK and MAX9121EXK-T share identical SC70-5 packaging, pinout, and open-drain output architecture. The key difference is that MAX9121EXK-T integrates a 1.252V ±1.75% reference (increasing supply current to 600nA), while MAX9120EXK omits the reference to achieve 350nA operation - trading reference convenience for ultra-low power.