Analog Devices Inc./Maxim Integrated MAX951ESA

Overview

MAX951ESA from Maxim Integrated is a micropower single-supply analog IC integrating a unity-gain-stable operational amplifier, a comparator with internal 1.2V ±2% bandgap reference, and rail-to-rail output stages in an 8-pin SO package. It operates from 2.7V to 7V, draws 7μA typical supply current, and supports common-mode input down to VSS and outputs swinging from VSS to VDD - enabling use in battery-powered smoke detectors and infrared receiver front ends.

For engineers reviewing the MAX951ESA datasheet, MAX951ESA pinout, MAX951ESA application, or MAX951ESA equivalent, key selection considerations include its integrated reference accuracy, ultra-low quiescent current under loaded conditions, rail-to-rail I/O capability at sub-7V supply, and verified performance across –40°C to +85°C industrial temperature range.

Technical Context

The MAX951ESA implements a CMOS-based op amp with internal unity-gain compensation and a separate high-impedance comparator whose inverting input is hardwired to the 1.2V reference. Both analog blocks share a common negative supply (VSS) and operate with input voltage ranges extending from VSS to VDD – 1.6V.

Its comparator features ±3mV internal hysteresis, continuous 40mA sourcing capability, and glitch-free switching - eliminating power-supply transients during logic transitions. The op amp maintains linearity driving ≥1000pF loads while sustaining <7μA total supply current, enabled by a proprietary high-gain output stage architecture.

Key Specifications

Pinout & Package

MAX951ESA uses an 8-pin SO (Small Outline) package with standard JEDEC MS-012AC footprint (body size 4.9mm × 3.9mm, lead pitch 1.27mm). Pin 1 is marked with a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar op amp + comparator + reference applications.

Compared with MAX952ESA, the MAX951ESA offers guaranteed unity-gain stability and lower supply current, making it preferable for simple buffers and low-power threshold detection; versus TLV2304IDR, it delivers tighter integration and 42% lower quiescent current but less flexibility in channel assignment.

Availability

MAX951ESA is available at Aetrix Electronics and suitable for battery-powered smoke detectors, infrared remote receivers, low-frequency alarm systems, and portable barcode readers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX951ESA 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 consumer systems.

The MAX951–MAX954 family was engineered to consolidate op amp, comparator, and reference functions into ultra-low-power, single-supply 8-pin solutions for space-constrained, battery-operated safety and sensing equipment.

FAQ

What is the maximum capacitive load the MAX951ESA op amp can drive while maintaining stability?

The MAX951ESA op amp is specified to drive up to 1000pF loads while remaining stable, as confirmed in the Typical Operating Characteristics (Figure MAX951–954 TOC12). This capability eliminates need for external isolation resistors in ADC interface or cable-driving applications, and is enabled by its internally compensated unity-gain architecture. The MAX951ESA maintains phase margin >45° under these conditions per manufacturer characterization.

Does the MAX951ESA reference output require external decoupling?

No, the MAX951ESA reference output must not be bypassed. The internal 1.2V bandgap reference is designed to be stable only for capacitive loads under 100pF; adding external capacitance causes oscillation or regulation error. Layout best practice is to route the REF pin directly to the comparator's inverting input (pin 6) or to high-impedance nodes without added capacitance, as stated in the Applications Information section.

Can the MAX951ESA comparator operate with input voltages beyond the supply rails?

Yes - the MAX951ESA comparator inputs tolerate voltages up to 300mV beyond VSS or VDD without damage, per Absolute Maximum Ratings. However, input voltages outside the common-mode range (VSS to VDD – 1.6V) cause degraded performance including increased offset and reduced speed. Operation above VDD or below VSS should be limited to transient fault conditions, not steady-state signal handling.

What is the guaranteed operating temperature range for the MAX951ESA part number?

The MAX951ESA is rated for operation from –40°C to +85°C, as explicitly defined in the Ordering Information table (page 12 of the datasheet). This industrial temperature grade ensures reliable performance in outdoor alarm systems, automotive cabin sensors, and portable test equipment exposed to ambient thermal extremes.

How does the internal hysteresis of the MAX951ESA comparator improve noise immunity?

The MAX951ESA comparator includes ±3mV internal hysteresis, creating a 6mV input voltage window between upper and lower switching thresholds. This prevents multiple output toggles when input signals hover near the trip point due to noise or slow slew rates - a critical feature for reliable operation in photodiode receivers and smoke detector analog front ends where signal edges are inherently sluggish.