LM20 Temperature Sensor: Features, Uses, and Specifications

The LM20 is a precision analog temperature sensor from Texas Instruments that provides a simple, low-power, and accurate solution for temperature measurement in a wide variety of applications. Designed for low voltage systems, the LM20 offers a linear analog voltage output that corresponds to the ambient temperature, making it an ideal choice for embedded systems, battery-operated devices, and temperature monitoring applications.

In this article, we’ll explore the key features, applications, and specifications of the LM20 temperature sensor, and why it's a popular choice among electronics designers.

Key Features of LM20

Low Power Consumption: Only 8 μA of typical supply current

Low Voltage Operation: Works from 2.4V to 5.5V supply

High Accuracy: ±1.5°C typical accuracy from –30°C to +100°C

Analog Voltage Output: Linearly decreases with increasing temperature

Fast Response Time: Rapid tracking of ambient temperature changes

Compact Package: Available in SC70, SOT-23, and TO-92 packages

No Calibration Required: Factory-trimmed for accuracy

Electrical Specifications

Parameter Typical Value

Supply Voltage 2.4V to 5.5V

Supply Current 8 µA (typical)

Output Voltage Range 1.5V to 0.1V (approx.)

Accuracy ±1.5°C (–30°C to +100°C)

Operating Temperature Range –55°C to +130°C

Temperature Coefficient –11.77 mV/°C (typical)

Package Types TO-92, SC70, SOT-23

How LM20 Works

The LM20 outputs a voltage that decreases linearly with increasing temperature. This voltage can be read by an ADC (Analog-to-Digital Converter) in a microcontroller or compared using analog circuits. Its negative temperature coefficient makes it easy to translate the output voltage into temperature using a simple formula or lookup table.

Example Output

At:

0°C, output ≈ 1.6V

25°C, output ≈ 1.2V

100°C, output ≈ 0.2V

Common Uses of LM20

1. CPU and Electronics Temperature Monitoring

Monitor thermal conditions in computers, servers, and embedded systems.

2. Battery-Powered Applications

Low power consumption makes it ideal for wearables, IoT, and remote sensors.

3. Industrial Equipment

Track environmental conditions in automation systems and enclosures.

4. Automotive Electronics

Monitor cabin or engine compartment temperatures.

5. Medical Devices

Use in portable diagnostic equipment or health monitors.

6. Smart Home Devices

Thermostats, climate controllers, and air quality systems.

Advantages of Using LM20

Easy to interface with any microcontroller with an ADC

Reliable and stable temperature measurement over a wide range

No need for calibration in most applications

Operates in harsh environments (wide temperature range)

Minimal external components needed

The LM20 temperature sensor is a compact, energy-efficient, and highly accurate device that simplifies temperature sensing in a wide range of applications. Its analog output, low power consumption, and wide operating range make it an excellent choice for modern embedded systems, especially in low-voltage, battery-operated environments.

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