Analog Devices Inc./Maxim Integrated LM4040AEX3-3.3+T

Overview

LM4040AEX3-3.3+T from Maxim Integrated is a precision 3.3V two-terminal shunt voltage reference in SC70-3 package, featuring 0.1% initial accuracy, ±100ppm/°C temperature coefficient over –40°C to +125°C, 60μA–15mA operating current range, and 50µVRMS wideband noise (10Hz–10kHz). It serves as a stable reference in battery-powered analog signal chains and high-reliability industrial sensor front-ends.

For engineers reviewing the LM4040AEX3-3.3+T datasheet, LM4040AEX3-3.3+T pinout, LM4040AEX3-3.3+T application, or LM4040AEX3-3.3+T equivalent, key selection criteria include guaranteed A-grade accuracy at extended temperature, no-output-capacitor stability, low dynamic impedance (<1.0Ω), and RoHS-compliant SC70 footprint compatibility with space-constrained PCB layouts.

Technical Context

The LM4040AEX3-3.3+T implements a laser-trimmed bandgap core with internal pass transistor, operating as a precision shunt device requiring only reverse bias current between 60μA and 15mA to maintain stable 3.300V output. Its architecture eliminates need for external stabilization capacitors while tolerating arbitrary capacitive loads.

Guaranteed performance across –40°C to +125°C includes ≤±22mV total overtemperature tolerance (A-grade), ≤1.2mV voltage change over 1mA–15mA current variation, and ≤1.0Ω dynamic impedance at 1mA/120Hz - enabling use in automotive engine control units and industrial process transmitters where thermal drift and load transients must be tightly controlled.

Key Specifications

Pinout & Package

LM4040AEX3-3.3+T uses the 3-pin SC70 surface-mount package (1.8mm × 1.8mm), 50% smaller than SOT23 equivalents, with exposed pad not connected and RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with TLVH431ACDBVR and ADR3433ARJZ-R7, LM4040AEX3-3.3+T delivers fixed 3.3V output in the smallest possible footprint with guaranteed A-grade accuracy and automotive temperature range - making it optimal for shunt-regulated systems where board area, thermal stability, and production calibration cost are critical constraints.

Availability

LM4040AEX3-3.3+T is available at Aetrix Electronics and suitable for portable medical sensors, automotive engine control units, industrial process transmitters, and IoT edge node power management requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM4040AEX3-3.3+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 industrial, automotive, and communications markets with emphasis on reliability, miniaturization, and low-power operation.

The LM4040 product line delivers micropower shunt voltage references optimized for space-critical, high-stability applications including battery-powered instrumentation, automotive subsystems, and industrial sensor interfaces where fixed-output accuracy and thermal robustness are essential.

FAQ

What is the guaranteed reverse breakdown voltage tolerance for LM4040AEX3-3.3+T over its full operating temperature range?

The LM4040AEX3-3.3+T guarantees ±22mV (±0.67%) total reverse breakdown voltage tolerance over –40°C to +125°C, calculated as ±3.0mV room-temperature tolerance plus ±100ppm/°C × 100°C × 3.3V = ±33mV worst-case drift, bounded by design to ±22mV per datasheet Note 2. This ensures consistent 3.300V reference performance in automotive and industrial environments without recalibration.

Can LM4040AEX3-3.3+T operate stably without an external output capacitor?

Yes, LM4040AEX3-3.3+T is inherently stable with any capacitive load and requires no external output capacitor - a key differentiator from many competing shunt references. This is confirmed in the Applications Information section and Typical Operating Characteristics, where stability is demonstrated with 0µF to 10µF output capacitance. The internal bandgap architecture and low dynamic impedance (<1.0Ω) eliminate phase-margin concerns.

What is the minimum operating current required for LM4040AEX3-3.3+T to maintain regulation?

The LM4040AEX3-3.3+T requires a minimum operating current of 67µA at +25°C and up to 73µA across –40°C to +125°C (per Electrical Characteristics table for 3.3V A-grade). Maintaining ≥67µA ensures the device remains in reverse breakdown and delivers its specified 3.300V output with full accuracy and temperature coefficient performance.

Is LM4040AEX3-3.3+T qualified for automotive applications?

Yes, LM4040AEX3-3.3+T is AEC-Q100 qualified (Grade 1) for automotive applications, as explicitly stated in the Benefits and Features section and confirmed by its –40°C to +125°C operating temperature range and qualification status in the Ordering Information table. It is suitable for use in engine control units, body electronics, and ADAS subsystems where reliability under thermal stress is mandatory.

How does the SC70-3 package of LM4040AEX3-3.3+T compare in size to the SOT23-3 variant?

The SC70-3 package used by LM4040AEX3-3.3+T measures 1.8mm × 1.8mm, which is 50% smaller than the standard SOT23-3 package (2.9mm × 1.6mm), as stated in the General Description. This reduction enables higher component density in compact designs such as wearable health monitors and multi-sensor IoT nodes, while maintaining identical pinout and electrical behavior.