About LM35 :


The LM35 is an integrated circuit sensor that can be used to measure temperature with an electrical output proportional to the temperature (in oC).The LM35 device has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling.

Why Use LM35s To Measure Temperature?

  • You can measure temperature more accurately than a using a thermistor.
  • The sensor circuitry is sealed and not subject to oxidation, etc.
  • The LM35 generates a higher output voltage than thermocouples and may not require that the output voltage be amplified.

What Does an LM35 Do?  How does it work?

  • It has an output voltage that is proportional to the Celsius temperature.
  • The scale factor is .01V/oC
  • 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.

Temperature Sensor LM35 using ADC and LPC2148

Circuit Diagram :