Analog Devices Inc./Maxim Integrated MAX4274BKEUA+

Overview

MAX4274BKEUA+ from Maxim Integrated is a single-channel, fixed-gain, rail-to-rail output operational amplifier with internal precision gain-setting resistors and ±17V input fault protection. It delivers noninverting gain of +5V/V, operates from +2.5V to +5.5V single supply, consumes only 355µA typical supply current, and achieves 330kHz −3dB bandwidth. It is used in low-side current-sense amplification and photodiode preamplifier circuits requiring high DC accuracy and compact layout.

For engineers reviewing the MAX4274BKEUA+ datasheet, MAX4274BKEUA+ pinout, MAX4274BKEUA+ application, or MAX4274BKEUA+ equivalent, key selection criteria include guaranteed 0.1% gain accuracy (RF/RG), rail-to-rail output swing into 1kΩ, stability with up to 470pF capacitive load, and VCC/2 biasing absence-confirming it is the non-biased variant versus MAX4275.

Technical Context

The MAX4274BKEUA+ integrates a decompensated rail-to-rail op-amp core with laser-trimmed on-chip feedback resistors (RF/RG) optimized for +5V/V noninverting gain. Its internal compensation targets 330kHz −3dB bandwidth and 23MHz gain-bandwidth product, enabling higher usable bandwidth than unity-gain-stable alternatives at this gain setting.

Input stage includes back-to-back SCR structures and diode clamps with 5kΩ series limiting on IN+, allowing ±17V fault tolerance without phase reversal or excessive current draw (<3.5mA). The inverting input (IN−) connects directly to RG, constraining its voltage range to within supply rails to avoid distortion.

Key Specifications

Pinout & Package

SOT23-5 package: ultra-compact 2.9mm × 1.6mm footprint with 0.95mm pitch, suitable for space-constrained portable and embedded designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-gain amplifier applications.

Compared with MAX4174BKEUA+, the MAX4274BKEUA+ offers extended temperature operation; compared with MAX4275BKEUA+, it provides design flexibility for externally controlled IN+ biasing-critical for precision DC-coupled current sensing and calibrated sensor interfaces.

Availability

MAX4274BKEUA+ is available at Aetrix Electronics and suitable for portable instruments, smart-card readers, and low-side current-sense applications requiring stable component supply, guaranteed 0.1% gain accuracy, and extended −40°C to +125°C operating temperature range.

Supply support for MAX4274BKEUA+ 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 industrial, automotive, communications, and consumer applications.

The MAX4274BKEUA+ belongs to the GainAmp™ family of fixed-gain amplifiers, engineered to replace discrete op-amp-plus-resistor configurations with factory-trimmed internal resistors-reducing board area, cost, and gain error in sensor signal chains and portable equipment.

FAQ

What is the gain configuration and value of the MAX4274BKEUA+?

The MAX4274BKEUA+ is a noninverting fixed-gain amplifier with a precisely trimmed +5V/V gain. This value is achieved using internal laser-trimmed resistors (RF/RG), delivering ±0.1% gain accuracy across temperature. Unlike open-loop op-amps, the MAX4274BKEUA+ requires no external feedback components, making it ideal for space-constrained and high-reliability applications where gain stability is critical.

Does the MAX4274BKEUA+ include internal VCC/2 biasing on the IN+ pin?

No, the MAX4274BKEUA+ does not include internal VCC/2 biasing. It is the non-biased variant in the MAX427x family. For applications requiring self-biasing of the noninverting input (e.g., AC-coupled single-supply designs), the MAX4275BKEUA+ should be selected instead. The MAX4274BKEUA+'s IN+ pin is a direct, unbuffered input requiring external biasing for proper DC operating point establishment.

What is the maximum capacitive load the MAX4274BKEUA+ can drive without oscillation?

The MAX4274BKEUA+ is stable with capacitive loads up to 470pF when driving into a resistive load (e.g., 100kΩ), per Maxim's Electrical Characteristics table. This eliminates the need for an output isolation resistor in most filter or cable-drive applications. For loads exceeding 470pF, a series isolation resistor (e.g., 100Ω) is recommended to maintain phase margin and prevent peaking or ringing.

What is the operating temperature range of the MAX4274BKEUA+?

The MAX4274BKEUA+ is rated for operation from −40°C to +125°C, qualifying it for extended industrial and automotive under-hood applications. This exceeds the −40°C to +85°C range of the pin-compatible MAX4174BKEUA+, making the MAX4274BKEUA+ the preferred choice where high-temperature reliability is required without redesigning the PCB layout.

How does the ±17V input fault protection work in the MAX4274BKEUA+?

The MAX4274BKEUA+ incorporates back-to-back SCR structures and diode clamps at both IN+ and IN− pins. When either input is overdriven beyond the supply rails by up to ±17V, the SCRs conduct and limit current to <3.5mA-protecting both the amplifier and upstream signal source. This architecture prevents phase reversal and latch-up, enabling robust operation in noisy or transient-prone environments such as motor control or industrial I/O interfaces.