Hi, I am currently working on a university project that utilises piezoelectric sensors. To amplify the output from my sensor I have designed a charge amplifier which I am building in PSpice so that I can get simulation information for the gain and operational bandwidth. My problem is I don't know how to add a charge source to represent my sensor.

I have already looked on line but have found nothing relevant for the PSpice version I'm using (Student 9.1) and can't find anything in the default libraries that were downloaded with my version. If anyone could point me to a part that can be used as a charge source or a method for creating one it would be greatly appreciated.

Thanks,
Sam

 

What are the characteristics of this "charge source"? Likely it can be simulated by either a voltage source or a current source.

 

Thanks for your reply, you've actually got me thinking. I've found the available literature to be fairly limited but I do know is it has a sensitivity of -4.3pC/N. I also know that the expected input force on my system verses time. The most rapid change in force is +2kN over 35ms while the greatest negative change is a decrease o 1kN over 35ms. Would I need to just create current source with the equation I=dQ/dt?

 

Thanks for your reply, you've actually got me thinking. I've found the available literature to be fairly limited but I do know is it has a sensitivity of -4.3pC/N. I also know that the expected input force on my system verses time. The most rapid change in force is +2kN over 35ms while the greatest negative change is a decrease o 1kN over 35ms. Would I need to just create current source with the equation I=dQ/dt?

That should work to give a reasonable simulation. For the two different values of current you can place two current sources in parallel (not series).

 

Thanks. I imagine parametric analysis will work too.