Hi,
I've got 1Khz (and the harmonics 2K,3K..) noises in the LINE-IN inputs while sampling a Piezo sensors that connected through self-built analog circuit, a pre-amp\Active filter.
My analog circuit is feeded from the 3.3V and GND of the Teensy,
I tried to create some LPF by add 100ohm resistor and parallel 10u cap to ground but it didnt help much...
This is my Active-filter\pre-amp, The 1.2K (R6) is the resistor that creates together with the 2.2uF cap thats appears in the Teensy Audio board line in.. this create LPF at 60Hz to decouple the DC and remove the 50Hz noises...
The main problem is that I cant separate the analog and digital supply - my system is feeded only by the USB of the teensy.
Any suggestion how can I get red of this noises?
By the way i tried to take the 3.3V from the ponint after the Ferrite 600 in the teensy and still same noises...
()
Thanks in advance
I've got 1Khz (and the harmonics 2K,3K..) noises in the LINE-IN inputs while sampling a Piezo sensors that connected through self-built analog circuit, a pre-amp\Active filter.
My analog circuit is feeded from the 3.3V and GND of the Teensy,
I tried to create some LPF by add 100ohm resistor and parallel 10u cap to ground but it didnt help much...
This is my Active-filter\pre-amp, The 1.2K (R6) is the resistor that creates together with the 2.2uF cap thats appears in the Teensy Audio board line in.. this create LPF at 60Hz to decouple the DC and remove the 50Hz noises...
The main problem is that I cant separate the analog and digital supply - my system is feeded only by the USB of the teensy.
Any suggestion how can I get red of this noises?
By the way i tried to take the 3.3V from the ponint after the Ferrite 600 in the teensy and still same noises...
()
Thanks in advance