LM4040 Voltage Reference Datasheet, Features, Pinout, and Applications
Update Time: Apr 10, 2025 Readership: 523
Contents
The LM4040 is a precision shunt voltage reference designed for high accuracy and low power consumption. Manufactured by Texas Instruments, this device provides a fixed reference voltage, making it ideal for analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and precision measurement systems.
Overview of LM4040
Engineered for applications where board space is limited, the LM4040 precision voltage reference comes in compact SC70 and SOT-23 surface-mount packages. Its advanced architecture eliminates the need for an external stabilizing capacitor, ensuring stability across a wide range of capacitive loads and simplifying implementation.
To further ease design integration, the LM4040 is offered in a variety of fixed reverse breakdown voltages, including 2.048V, 2.5V, 3V, 4.096V, 5V, 8.192V, and 10V. The minimum operating current varies by model, starting at 60 μA for the 2.5V version and increasing to 100 μA for the 10V option. All versions are rated for a maximum operating current of 15 mA.
To achieve tight accuracy, the LM4040 undergoes fuse and Zener-zap trimming during wafer sort, resulting in a typical voltage precision better than ±0.1% at 25°C (A grade). A curvature correction technique within the bandgap reference circuit, along with low dynamic impedance, helps maintain consistent voltage accuracy across varying temperatures and load conditions.
Additionally, the LM4041 series is available for applications requiring either an adjustable version or a fixed 1.2V reverse breakdown voltage.
Shunt Reference Application Schematic
LM4040 Features
Automotive-Grade Reliability
– LM4040-N-Q1 meets AEC-Q100 qualifications for automotive use
– Grade 1: Operates from −40°C to +125°C ambient
– Grade 3: Operates from −40°C to +85°C ambient
Compact Package Selection
– Offered in space-saving SOT-23, TO-92, and SC70 packages
No Output Capacitor Required
– Stable performance with or without capacitive loads
Fixed Voltage Options
– Available reverse breakdown voltages: 2.048V, 2.5V, 3V, 4.096V, 5V, 8.192V, 10V
Highlighted Electrical Characteristics (2.5V LM4040-N)
– Output voltage tolerance (A Grade at 25°C): ±0.1% max
– Low output noise over 10 Hz to 10 kHz: 35 μVrms (typical)
– Broad operating current range: 60 μA to 15 mA
– Temperature operation:
• Industrial range: −40°C to +85°C
• Extended range: −40°C to +125°C
– Tight temperature coefficient: Maximum 100 ppm/°C
LM4040 Pinout
Pin Configuration
| PIN | I/O | DESCRIPTION | |||
| NAME | SOT-23 | TO-92 | SC70 | ||
| Anode | 2 | 3 | 1 | O | Anode pin, normally grounded |
| Cathode | 1 | 2 | 3 | I/O | Shunt Current/Output Voltage |
| * | 3 | 1 | 2 | — | Must float or connect to anode |
| NC | — | — | 4.5 | — | No connect |
Absolute Maximum Ratings
Functional Block Diagram
LM4040 Applications
Field Transmitters
The LM4040 is commonly used in field transmitters, where accurate voltage references are critical for maintaining sensor calibration and signal integrity. These transmitters operate in remote or harsh environments, often requiring components that deliver stable performance despite fluctuations in temperature or supply voltage. The LM4040 provides a precise, low-drift voltage reference, making it ideal for ensuring consistent output in 4–20 mA loop systems and other analog signal transmission applications used in industrial process control and environmental monitoring.
Energy Infrastructure
Within energy infrastructure systems—such as smart grid devices, metering equipment, and renewable energy inverters—the LM4040 serves as a reliable voltage reference to support high-precision measurement and monitoring circuits. Its low temperature coefficient and consistent output improve the accuracy of analog-to-digital conversion, helping to ensure stable operation of energy control systems. Whether used in solar panel inverters, battery management systems, or energy distribution monitoring, the LM4040 enhances the reliability and efficiency of power management and control circuits.
Data Acquisition
In data acquisition systems, where precision is essential for capturing analog signals and converting them into digital form, the LM4040 provides a dependable voltage reference for ADCs and DACs. Its compact size, low power consumption, and stable output make it well-suited for multichannel data logging, test equipment, and laboratory instrumentation. By maintaining a consistent reference voltage, the LM4040 improves the accuracy of signal measurements in scientific, industrial, and medical applications.
Analog Input Module
Analog input modules used in PLCs (programmable logic controllers) and automation equipment benefit significantly from the stable reference provided by the LM4040. These modules require accurate voltage references to ensure reliable measurement of input signals from a variety of sensors and transducers. The LM4040 helps maintain signal fidelity and reduces error margins in measurement channels, making it a valuable component in control systems where precision and repeatability are crucial.
Automotive
In automotive electronics, the LM4040 is used in systems that demand dependable voltage references under wide temperature and voltage ranges. It supports applications such as battery monitoring, engine control modules, and sensor interfacing circuits. Its ability to withstand automotive-grade operating conditions while delivering consistent performance makes it suitable for integration into safety-critical and performance-sensitive subsystems, ensuring reliability in both electric and conventional vehicles.
Audio and Video
The LM4040 also finds use in high-fidelity audio and video equipment, where clean and accurate voltage references contribute to low-noise analog circuitry. In audio preamplifiers, DACs, and video processing units, voltage reference stability directly impacts output quality. By minimizing fluctuations and noise in the reference signal, the LM4040 helps maintain sound clarity and visual signal integrity, supporting consistent performance in professional and consumer-grade AV systems.
LM4040 Package
The LM4040 is available in SOT-23, SC70, and TO-92 packages, providing flexibility for both surface-mount and through-hole assembly. These package options allow integration into compact, high-precision designs while maintaining excellent thermal and electrical performance.
LM4040 Manufacturer
The LM4040 is manufactured by Texas Instruments, a world-renowned leader in analog and embedded processing semiconductor technology. With decades of expertise in power management, TI delivers high-precision voltage reference ICs like the LM4040 that are trusted in mission-critical industrial, automotive, medical, and consumer applications.
Texas Instruments is known for its robust quality standards, innovative circuit design, and comprehensive technical support, ensuring that products like the LM4040 meet the demanding performance and reliability standards of modern electronics. Their extensive portfolio supports a broad range of applications, from low-power mobile devices to precision instrumentation systems.
LM4040 Datasheet
The LM4040 Datasheet provides complete information on pin configuration, electrical characteristics, thermal parameters, and application notes to guide engineers in system design and optimization.
LM4040 vs. Other Voltage References
| Feature | LM4040 | TL431 | ADR4525 |
|---|---|---|---|
| Output Voltage | 2.5V to 5.0V | Adjustable | Fixed (2.5V) |
| Initial Accuracy | ±0.1% (typ) | ±1% (typ) | ±0.02% (typ) |
| Operating Current | 60 µA – 15 mA | >500 µA | 1.2 mA (typ) |
| Package Options | SOT-23, TO-92, SC70 | TO-92, SOT-23 | MSOP, SOIC |
Conclusion
The LM4040 Voltage Reference is a compact, high-precision solution for voltage regulation in low-power and high-accuracy applications. Its tight voltage tolerance, low temperature drift, and ultra-low operating current make it a dependable choice for precision analog systems, battery-powered devices, and data converters. With support from Texas Instruments' legacy of quality, the LM4040 ensures long-term reliability and performance.
Extended Reading
FAQ
-
What output voltages are available for the LM4040?
The LM4040 is available in 2.5V, 4.096V, and 5.0V fixed voltage options.
-
Is an output capacitor required for the LM4040?
No external output capacitor is required for stable operation, simplifying circuit design.
-
What is the typical operating current of the LM4040?
The LM4040 typically operates at 60 µA, making it ideal for low-power systems.
-
Can the LM4040 be used in high-precision analog designs?
Yes, the LM4040’s tight accuracy and low temperature coefficient make it well-suited for precision analog and data acquisition systems.
LM4040AIM3-2.5 In Stock: 5,445 Pcs
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