04-12-2012, 04:34 PM
Temperature Sensor - The LM35
Temperature Sensor.docx (Size: 135.99 KB / Downloads: 39)
What Does an LM35 Do? How does it work?
o It has an output voltage that is proportional to the Celsius temperature.
o The scale factor is .01V/oC
o The LM35 does not require any external calibration or trimming and maintains an accuracy of +/-0.4 oC at room temperature and +/- 0.8 oC over a range of 0 oC to +100 oC.
What Can You Expect When You Use An LM35?
o You will need to use a voltmeter to sense Vout.
o The output voltage is converted to temperature by a simple conversion factor.
o The sensor has a sensitivity of 10mV / oC.
o Use a conversion factor that is the reciprocal, that is 100 oC/V.
o The general equation used to convert output voltage to temperature is:
Temperature ( oC) = Vout * (100 oC/V)
So if Vout is 1V , then, Temperature = 100 oC
The output voltage varies linearly with temperature.