LM4140 Precision Voltage Reference: Features, Uses, and Specifications

The LM4140 is a high-precision, low-noise voltage reference developed by Texas Instruments, designed for applications that demand exceptional accuracy, low temperature drift, and ultra-low noise performance. It is widely used in data acquisition systems, high-resolution analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and precision instrumentation.

In this article, we’ll explore the key features, technical specifications, and common uses of the LM4140, and why it’s a trusted choice for precision analog designs.

 

What is LM4140?

 

The LM4140 is a high-precision voltage reference that provides a stable output voltage regardless of temperature, supply voltage variations, or load conditions. It features an initial accuracy as tight as ±0.1 mV, ultra-low temperature coefficient (as low as 3 ppm/°C), and low output noise, making it ideal for high-performance analog systems.

 

 

Key Features of LM4140

 

·        Output Voltage Options: 1.024V, 2.048V, 2.5V, 4.096V, 5V

·        Initial Accuracy: ±0.1 mV typical

·        Ultra-Low Temperature Coefficient: As low as 3 ppm/°C

·        Low Noise Output: 8 µVpp (0.1 Hz to 10 Hz)

·        Low Supply Current: Typically 70 µA

·        High Output Drive Capability: Can source up to 10 mA

·        Thermal Shutdown Protection

·        Package Types: TO-92, SOIC-8, and MSOP-8

·        Factory-Trimmed for High Precision

 

LM4140 Specifications

 

Parameter                                         Value                          

Output Voltage Options                1.024V, 2.048V, 2.5V, 4.096V, 5V  

Initial Accuracy                                ±0.1 mV (typ), ±0.2% (max)        

Temperature Coefficient               3 ppm/°C (typ)                    

Supply Voltage Range                     4.5V to 15V                       

Output Current                                 Up to 10 mA                       

Output Noise (0.1 Hz to 10 Hz)        8 µVpp                            

Quiescent Current                           70 µA (typ)                       

Operating Temperature Range           –40°C to +125°C                   

Packages                                           SOIC-8, MSOP-8, TO-92              

 

 

Common Applications of LM4140

 

1. High-Resolution ADCs and DACs

   Provides a stable voltage reference for 16-bit and 24-bit data converters.

 

2. Precision Instrumentation

   Used in scientific instruments and sensors requiring ultra-low drift and high accuracy.

 

3. Medical Equipment

   Supports reliable performance in medical devices where data integrity is critical.

 

4. Calibration and Test Equipment

   Serves as a reference voltage in voltage calibration sources and precision testers.

 

5. Data Acquisition Systems

   Ensures consistent and accurate analog measurements.

 

6. Analog Signal Processing

   Delivers a reliable reference voltage in low-noise analog signal chains.

 

 

Benefits of Using LM4140

 

·        High Accuracy: Factory-trimmed for tight output tolerance.

·        Stable Over Temperature: Ideal for environments with fluctuating conditions.

·        Low Noise: Critical for sensitive analog circuits like audio or sensor systems.

·        Low Power Consumption: Excellent for portable and battery-operated systems.

·        Multiple Voltage Options: Flexible integration in a variety of circuit designs.

     For Video tutorial