Analog Devices Inc./Maxim Integrated MAX951ESA-T

Overview

MAX951ESA-T 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 - ideal for battery-powered smoke detectors and infrared receiver front ends.

For engineers reviewing the MAX951ESA-T datasheet, MAX951ESA-T pinout, MAX951ESA-T application, or MAX951ESA-T equivalent, key selection criteria include its integrated reference accuracy, ultra-low quiescent current under loaded conditions, rail-to-rail output swing capability, and guaranteed operation across –40°C to +85°C industrial temperature range.

Technical Context

The MAX951ESA-T 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 parasitic supply feedback during logic transitions. The op amp maintains linearity while driving up to 1000pF loads and exhibits <3mV input offset voltage over temperature.

Key Specifications

Pinout & Package

MAX951ESA-T is housed in an 8-pin SO (Small Outline) package, 3.9mm × 4.9mm, with standard 1.27mm pitch and gull-wing leads. RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX952ESA-T, MAX951ESA-T offers lower system-level component count due to integrated reference and unity-gain stability, while TLV2304IDR trades integration for broader supply range and independent channel control - making MAX951ESA-T optimal for space- and power-constrained safety sensors.

Availability

MAX951ESA-T is available at Aetrix Electronics and suitable for battery-powered instruments, smoke detectors, and infrared receivers requiring stable component supply with guaranteed long-term manufacturability and industrial temperature support.

Supply support for MAX951ESA-T 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, interface, and reliability-critical applications.

The MAX951–MAX954 family was engineered specifically for ultra-low-power, single-supply sensor signal conditioning and threshold detection in portable and safety-critical systems - prioritizing micropower operation, integrated reference accuracy, and robust comparator behavior over speed or wide supply range.

FAQ

What is the operating temperature range of the MAX951ESA-T?

The MAX951ESA-T is rated for operation from –40°C to +85°C, meeting industrial-grade environmental requirements. This range is validated across all electrical parameters including reference voltage accuracy (±2%), input offset voltage (<3mV), and supply current (7μA typical), ensuring reliable performance in smoke detectors, handheld scanners, and outdoor alarm systems where ambient temperatures vary widely. The MAX951ESA-T's SO package supports this full range without derating.

Does the MAX951ESA-T require external compensation components for op amp stability?

No, the MAX951ESA-T op amp is internally compensated for unity-gain stability and requires no external capacitors or resistors to maintain phase margin. It remains stable driving capacitive loads up to 1000pF, which simplifies PCB layout in photodiode preamp or sensor buffer designs. This eliminates risk of oscillation in high-impedance nodes - a key advantage over decompensated alternatives like the MAX952ESA-T, which mandates minimum gain of 10V/V.

Can the internal 1.2V reference of the MAX951ESA-T be used to bias external circuitry?

Yes, the REF pin (Pin 6) of the MAX951ESA-T provides a buffered 1.2V ±2% output referenced to VSS and is specified to source/sink ±20μA. It is commonly used to bias the noninverting input of the op amp or set thresholds in external comparators. However, it must not be bypassed with capacitance (>100pF), and loading beyond ±20μA will degrade accuracy and regulation - verified in the Electrical Characteristics table under "Load Regulation".

What is the maximum capacitive load the MAX951ESA-T op amp can drive without instability?

The MAX951ESA-T op amp is characterized to drive up to 1000pF capacitive loads while maintaining stability and minimal overshoot, as confirmed in the "OP AMP PERCENT OVERSHOOT vs. CAPACITIVE LOAD" graph (Figure TOC12). This capability supports direct connection to RC anti-aliasing filters or long PCB traces in smoke detector sensor paths without requiring isolation resistors or external compensation - a critical feature for maintaining signal fidelity in high-impedance, low-power measurement chains.

How does the MAX951ESA-T comparator handle slow-moving input signals?

The MAX951ESA-T comparator incorporates ±3mV internal hysteresis, which creates a 6mV input voltage window between upper and lower switching thresholds. This prevents output chatter caused by noise or gradual input changes - essential for reliable triggering in smoke detectors where chamber voltage rises slowly over seconds. The hysteresis is inherent and requires no external components, unlike discrete comparator solutions that demand positive feedback networks for noise immunity.