I opened another thread about this sensor a few days ago and we determined that it was the best to do to filter out any interference as per Fig3 of the datasheet (cf http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=lm35®=en&fileType=pdf)
I am using a 10k? resistor and a 1µF capacitor between the Vout and GND