LM35 is a Temperature sensor, whose output voltage changes, based on the surrounding temperature. It is a small and inexpensive IC that can be used to measure temperatures between -55 °C to 150 °C. It can easily connect with any Microcontroller that has AC/DC function or with Arduino.

Lm35 IC regulates voltage like +5V to the input pin and connected the ground pin to the ground of the circuit to measure the temperate in the form of voltage.

LM35 Temperature Sensor pins out

LM35 Temperature Sensor pins out

Pin 1 receives a positive DC voltage typically  5 volts. Pin 3 is the ground that receives the ground or negative current. Pin 2 is the output of the IC that is used to get output from the temperature sensor.

How Does LM35 Sensor Work

The LM35 sensor is linear i.e. 10mv/°C which means that every degree rises in temperature by 10mv. In this way, if the output of the LM35 sensor is 220mv/0.22V the temperature will be 22 °C. If the room temperature is 32 °C then the output of the sensor will be 320mv i.e. 0.32V.

Alternative to LM35 Temperature Sensor

If you want to read the degree Fahrenheit then use the LM34 Temperature sensor. It is the same as LM35 but its electrical output is proportional to Degrees Fahrenheit. LM34 has also same pins configuration and the same voltage range same like lm35.

LM35 Temperature Sensor Applications

LM35 Temperature Sensor Applications:

  • Mostly used to measure the temperature of a particular environment
  • Auto shutdown the thermal temperature applications.
  • Control the auto temperature of the fan or AC.
  • It is also used with a computer fan to control the heat of a system
  • Temperatures for HVAC applications.

LM35 Regulator Features:

  • Minimum volts -2 to 35 volts. Typically, 5V.
  • It Can measure temperatures between -55 °C to 150 °C
  • The output voltage is directly proportional (Linear) to temperature (i.e.) there will be a rise of 10mV (0.01V) for every 1 °C rise in temperature.
  • Accuracy is ±0.5 °C
  • The drain current is less than 60uA
  • Low-cost temperature sensor and easily available.
  • Suitable for remote applications
  • Available packages: TO-92, TO-220, TO-CAN, and SOIC.