I am converting 9V to 3.3V using LM317. But here i met a strange problem. LM317 output fluctuates with a humming noise. my circuit has 3 another ICs working in this 3.3Voltage. But no one is getting heated. do any one know any solution to this problem? thanks for the help... YOurs SaRIn.... --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .