I am using OPA2137 to pickup signals coming from an energy harvesting device (EHD).
I have attached a PPT with two slides. The first slide shows the OPA wiring (sorry for the graphics...) and the second slide shows the overall testing setup.
The problem is that the amplifier (Out A) goes immediately to saturation when connected to the batteries. This is before connecting the EHD to +InA. In addition, when I disconnect the ground of the PCB of the amplifier from the housing of the testing setup, the output (Out A) goes to zero-that is not saturated anymore. (I am feeding the EHD through the +inA because the EHD has high impedance and the oscillations is in the range of 1Khz.)
In slide 2 you can see the general setup. As you can see the OPA is inside the testing chamber. Maybe I need to house the OPA in a separate shielded package.
I appreciate very much your feedback!saturation problem.pptx