Lm35 Temperature sensor Features
LM35 Pin Out
Input voltage to lm35 can be from +4 volts to 30 volts. It consumes about 60 micro amperes of current. Lm35 has many family members few names are LM35C, LM35CA, LM35D, LM135, LM135A, LM235, LM335. All lm35 family members work on same principles but temperature measuring capacity varies and also they are available in many packages (SOIC, TO-220, TO-92, TO ).
Lm35 Working Principle (Understanding Lm35 Linear Scale Factor)
Lm35 temperature sensor circuit configuration
Although the first configuration did not need a resistor at output side but i recommend to connect an 80 k to 100 k resistor between vout and gnd pin. When i performed several experiments i noticed that the readings some time fluctuate and the vout pin floats. So a resistor between vout and gnd tights the vout pin low and prevents the pin from floating.
Steps to calculate temperature using Lm35 temperature sensor
Formula to convert voltage to temperature
The formula to convert voltage to centigrade temperature for Lm35 is
Centigrade Temperature = Voltage Read by ADC / 10 mV(mills Volt)
I divided by 10 mV because Linear scale factor is for Lm35 is 10mV.
Some projects that are created using Lm35 and different microcontrollers.