Other Parts Discussed in Thread: TINA-TI
I am trying to use the OPA365 as an inverting amplifier for the signal from this contact microphone sensor: http://www.mouser.com/ds/2/418/Contact_Microphone-769347.pdf . However the DC bias that I apply to the + input pin(1.65V) of the amplifier doesn't bias the output signal properly and there seems to be some sort of temporal response. The output signal ends being biased at 500mV after a while. Additionally this DC bias varies when I assemble the same circuit with a different OPA365 chip. This behaviour is quite unpredictable and I would appreciate if anyone could suggest a solution or if I am using the wrong amplifier for this application please let me know another that might be better suited for used with this sensor.
Thanks