Analog Devices Inc./Maxim Integrated MAX4040EUA

Overview

MAX4040EUA from Maxim Integrated is a single-channel, micropower, rail-to-rail input/output operational amplifier optimized for ultra-low-power, low-voltage portable systems. It operates from +2.4V to +5.5V single supply, draws only 10µA quiescent current, delivers 90kHz gain-bandwidth product, and swings within 10mV of rails with 100kΩ load - enabling precision signal conditioning in battery-powered sensor interfaces and portable instrumentation.

For engineers reviewing the MAX4040EUA datasheet, MAX4040EUA pinout, MAX4040EUA application, or MAX4040EUA equivalent, key selection criteria include its guaranteed -40°C to +85°C operation, 200µV input offset voltage, rail-to-rail common-mode range (VEE to VCC), unity-gain stability with up to 200pF capacitive loads, and SOT23-5 footprint compatibility for space-constrained designs.

Technical Context

The MAX4040EUA employs a dual-input-stage architecture combining NPN and PNP differential pairs to achieve true rail-to-rail input common-mode range extending from VEE to VCC. Its output stage uses complementary push-pull transistors capable of sourcing/sinking current to drive resistive loads down to 25kΩ while maintaining rail-to-rail swing.

This architecture enables stable operation at supply voltages as low as +2.4V, supports direct connection to decaying battery rails due to 85dB PSRR, and avoids phase reversal during overdriven input conditions - critical for reliable signal integrity in unregulated power environments.

Key Specifications

Pinout & Package

The MAX4040EUA is housed in a 5-pin SOT23 package (JEDEC MO-178AA), with pin 1 marked by a dot or beveled edge. Pin assignments are validated per Maxim's official pin configuration diagram (19-1377 Rev 1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar micropower rail-to-rail op amp applications.

Compared with TLV851DBVR and OPA316IDBVR, the MAX4040EUA uniquely balances 10µA supply current, 90kHz bandwidth, and ±200µV offset in a 5-pin SOT23 - making it optimal for battery-powered precision amplification where moderate speed and ultra-low power are both required.

Availability

MAX4040EUA is available at Aetrix Electronics and suitable for battery-powered sensor amplifiers, portable medical instrumentation, strain gauge interfaces, and low-voltage current monitoring requiring stable component supply across extended temperature ranges.

Supply support for MAX4040EUA 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, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX4040EUA belongs to the MAX4040–MAX4044 micropower rail-to-rail op amp family, engineered specifically for ultra-low-power, low-voltage portable systems where battery life, signal fidelity, and space constraints are critical.

FAQ

What is the maximum capacitive load the MAX4040EUA can drive without oscillation?

The MAX4040EUA is unity-gain stable with capacitive loads up to 200pF, as confirmed in the Electrical Characteristics table and Typical Operating Characteristics (Load Resistor vs. Capacitive Load graph). For loads exceeding 200pF, an isolation resistor (e.g., 1kΩ) between the output and load is recommended to maintain stability, though this introduces gain error due to voltage division. The MAX4040EUA does not require external compensation components under the specified condition.

Does the MAX4040EUA support dual-supply operation?

Yes, the MAX4040EUA supports dual-supply operation from ±1.2V to ±2.75V, as stated in the General Description. In dual-supply mode, VCC connects to the positive rail and VEE to the negative rail, preserving rail-to-rail input common-mode range (from VEE to VCC) and output swing capability. This configuration is useful in legacy industrial systems or bipolar sensor interfaces where ground-referenced signals are not feasible.

What is the input offset voltage drift over temperature for the MAX4040EUA?

The MAX4040EUA has a guaranteed input offset voltage drift of 2µV/°C over the -40°C to +85°C operating range, per the Electrical Characteristics table (TA = TMIN to TMAX section). This low drift ensures long-term stability in precision applications such as digital scales and medical instrumentation, where thermal gradients could otherwise introduce significant measurement error without calibration.

Can the MAX4040EUA be used as a comparator?

Yes, the MAX4040EUA can be used as a rail-to-rail input/output comparator, as explicitly described in the Applications Information section. Propagation delay depends on input overdrive (e.g., ~20µs for 100mV overdrive at +5V supply), and external hysteresis is recommended to prevent oscillation near threshold. However, quiescent current rises to ~28–35µA in saturation - still ultra-low compared to dedicated comparators - making it viable for low-duty-cycle wake-up detection.

Is the MAX4040EUA pin-compatible with other members of the MAX4040–MAX4044 family?

No, the MAX4040EUA is not pin-compatible with MAX4041, MAX4042, MAX4043, or MAX4044 variants. While all share the SOT23-5 package option, only the MAX4040 (single, no shutdown) matches the 5-pin pinout. MAX4041 adds SHDN on pin 6 (requiring 6-pin layout), and dual/quad versions use 8-pin or 14-pin packages. The MAX4040EUA's pin 1 (VCC), 2 (IN−), 3 (OUT), 4 (IN+), 5 (VEE) assignment is unique to the single-channel non-shutdown variant.