I have a 4th order bandpass filter which needs to be biased using 1/2 Vcc. I am trying to achieve this using a voltage follower. The bandpass filter was constructed using Multiple feedback topology as shown:
On Proteus I get a 100kHz center frequency and a 4kHz band pass at a gain of 1 AV.
Using a +2.5V simulation goes as expected, and gives the desired response.
I designed two voltage followers using LM324, and tested these in a separate project. I get 2.5V output as expected.
On adding the voltage followers, and connecting just one output of the voltage follower to the second stage of the op-amp, simulation still takes place without errors, but the response is not correct, as I need to bias both stages.
On connecting both voltage followers, I get an error. I cant understand why.
Any suggestions why this is happening would be appreciated.