Hello,
I'm having trouble configuring the input of the VCA822, I am using it as a single ended input and feeding it from a OPA378 OpAmp. My problem is the signal coming out of the OPA378 was riding on a 2.5V DC bias. I added a 22uF cap to cancel the 2.5V bias but the input of the VCA822 floated to -3.3V. Then I added a 12.7k resistor to ground which helped remove the -3.3V offset, but my output signal of the VCA822 is slightly distorted.
Can anyone recommend the best way to interface the OPA378 with the 2.5V DC bias, to the VCA822, and not distorting my signal? The input signal is a slow ECG signal. The image below is my current set-up.
Thanks!
Monse