AnsweredAssumed Answered

STM32F103RB ADC Noise

Question asked by brock.jamie on May 27, 2014
Latest reply on May 28, 2014 by sung.chen_chung
Hi
I'm having problems with noise on the STM32F103RB ADC.

At the VDDA pin there is 20mV pk-pk noise from a 300KHz switch regulator.
I am using the recommended 1uF || 10nF caps on the pin.

I was going to add a series ferrite to block the switching noise but when I came to look for the design steps it looks like ferrites are for noise in the MHz range.

Can anyone advise on options for putting a simple filter stage between my 3V3 rail and VDDA pin to attenuate the 300KHz switching noise.
I would like to attenuate by an order of magnitude, it is currently 20mV pk-pk

Any help would be highly appreciated
Thanks

Outcomes