I have setup the below circuit; a basic envelope detector, however I believe that the op-amp is struggling with the load capacitance.
With the 100nF cap removed, then the output of the op-amp behaves as expected following the input voltage (AC around 1.6v DC). The output of the op-amp is driven higher to make up for the diode voltage drop. (Below scope trace, blue input, red output).
However when the 100nF is added, then the op-amp is not drving the output high enough. It just stays around 1.6V. In theory the output voltage should rise to around 1.9V.
I added the 2.2K output series resistor to try and get round the issue, but it didn't help. Are there any obvious errors or ways around the issue?
It may be that I need to use a different op-amp.