Analog Devices Inc./Maxim Integrated MAX918EUK

Overview

MAX918EUK from Maxim Integrated is a nanopower, open-drain comparator with integrated 1.245V ±1.5% reference, guaranteed to operate from +1.8V to +5.5V supply, consuming only 750nA typical supply current, and featuring Beyond-the-Rails™ input range extending 200mV beyond VEE and VCC - ideal for 2-cell battery monitoring in portable medical instruments and telemetry systems.

For engineers reviewing the MAX918EUK datasheet, MAX918EUK pinout, MAX918EUK application, or MAX918EUK equivalent, this page delivers verified technical context, real-world design meaning of key specs (e.g., 4mV internal hysteresis, 190mV VOL at 1mA sink, 1.245V reference TC = 95ppm/°C), and validated alternative options for low-power threshold detection.

Technical Context

The MAX918EUK implements a rail-to-rail input stage with ESD-protected inputs operating from VEE −0.2V to VCC +0.2V, and an open-drain output capable of sinking up to 8mA while tolerating up to +6V on the output pin relative to VEE. Its internal 1.245V reference uses a 120nA current source and exhibits 95ppm/°C temperature coefficient over −40°C to +85°C.

Unlike conventional comparators, its break-before-make output architecture minimizes supply-current surges during switching - supply current increases by less than 100nA even at 1kHz output toggle frequency - eliminating need for large bypass capacitors in ultra-low-power battery systems.

Key Specifications

Pinout & Package

SOT23-5 package: 2.9mm × 1.6mm × 1.1mm body, 0.95mm pitch, surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV3691IDBVR and MAX40002ANSR, the MAX918EUK uniquely combines ultra-low current (750nA), precise 1.245V ±1.5% reference, and open-drain output in SOT23-5 - making it optimal for space-constrained, battery-critical designs requiring self-contained threshold detection.

Availability

MAX918EUK is available at Aetrix Electronics and suitable for 2-cell battery monitoring, ultra-low-power telemetry, and medical instrument power management requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MAX918EUK 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 communications systems.

The MAX917–MAX920 family was engineered specifically for nanopower, rail-aware threshold detection in battery-operated equipment - prioritizing supply current, input range, and integration over speed or drive strength.

FAQ

What is the maximum output sink current specification for MAX918EUK?

The MAX918EUK is specified to sink up to 8mA while maintaining VOL ≤ 400mV at VCC = 5V and TA = +25°C. At 1.8V supply and 1mA load, VOL is typically 190mV. The output stage is rated for 50mA short-circuit current, but continuous operation above 8mA may exceed thermal limits in SOT23-5 packaging. Always verify voltage drop and power dissipation in your specific layout and ambient conditions when using MAX918EUK.

Does MAX918EUK require external hysteresis for stable operation?

No - the MAX918EUK includes 4mV typical internal hysteresis, sufficient to prevent oscillation on slow or noisy inputs like thermistors or battery voltage ramps. External hysteresis is optional and only needed when larger hysteresis bands (e.g., >10mV) are required for noise immunity. The MAX918EUK datasheet provides resistor calculation methods for adding external hysteresis using positive feedback, but most applications function reliably using the built-in hysteresis alone.

Can MAX918EUK's internal reference be used to bias external circuits?

Yes - the IN−/REF pin of MAX918EUK delivers the 1.245V reference with ±1.5% accuracy and 95ppm/°C temperature coefficient. It can source or sink up to ±10nA while maintaining regulation within ±0.2mV/nA. For higher current demands (>100nA), buffer the reference with a low-input-bias op amp such as MAX406. Do not connect capacitive loads >1nF directly to the REF pin unless bypassed with a series resistor to maintain stability - the MAX918EUK reference is stable with any capacitive load when properly decoupled.

What is the input common-mode voltage range of MAX918EUK?

The MAX918EUK features a Beyond-the-Rails™ input stage with common-mode range from VEE −0.2V to VCC +0.2V. This allows direct sensing of signals referenced to ground (e.g., shunt voltage) or to supply rails (e.g., battery voltage) without level-shifting circuitry. Input bias current remains low (±0.15nA typical) within the rails, rising slightly outside due to ESD diode conduction - a known and characterized behavior documented in the MAX918EUK datasheet.

Is MAX918EUK pin-compatible with other devices in the MAX917–MAX920 family?

Yes - all MAX917–MAX920 variants in SOT23-5 package (including MAX917EUK, MAX918EUK, MAX919EUK, MAX920EUK) share identical pinout: Pin 1 = VEE, Pin 2 = IN−/REF, Pin 3 = IN+, Pin 4 = VCC, Pin 5 = OUT. This allows direct substitution between open-drain (MAX918/MAX920) and push-pull (MAX917/MAX919) versions, or between referenced (MAX917/MAX918) and reference-less (MAX919/MAX920) versions, provided the application accommodates the output type and reference presence. Always verify schematic connectivity and firmware logic when swapping MAX918EUK with another variant.