hi, in magnetic levitation project,i am using a fan management chip from Micrel (MIC502) as a driver to produce PWM to h-bridge LMD18201. but based on the datasheet of MIC502, input VT1 will affect the output at pin7, and the output should be a pulse waveform.. i supply VDD with 5V, VT1 with 1.5V to 3.5V, capacitor at pin2 is 0.1μF that is 30Hz, and pin3, pin4, pin5 to ground...but i cant get the PWM output,why? i have tried many ways to test it, but no PWM is produced.. i wonder is it my mistake to test it or the ic itself is burnt? can i have some suggestion on how to test the MIC502? thanks a lot..