what is the frequency range of noise introduced by a SMPS

[vahidkh6222]

hi,
I heard that there is some high freq noise introduced by switching mode power supplies. in my adc board i see some 20mhz intermodulation interference with my analog signal. I wonder if it might be because of computer's smps which I use as power supply...

 

[ashish_chauhan]

Re: what is the frequency range of noise introduced by a SMP

Hi
The switching noise introduced by smps are at the freqs of switching freq of smps and its harmonics. I dont think the intermodulation ur talking about is diue to ur computers smps.(coz smps usually are switching at a freq much less than 20 Mhz)