We are making an own ECG board , and currently we have some noise issues on the CHEST channels.
As an error search we go around the elements which are connected to the WCT, chest channels, power supply, etc.
What i found is that the noise almost disappears if i took out then external 100pF capacitance.
I attach some pictures about the external test signal we connect on the board.
Did you have some experiences with noise regarding this external cap?
It might happened that the noise is coming from the AVSS, as this cap is connected to that net.
A bigger resolution :
And the situation without the external cap. on WCT:
Thank you.
Best Regards,
Lou