Thank you Silicon Wizard,
it is used for detecting the amplitude of a sensor.
The sensor generates an AC signal proportional to the quantity measured. That amplitude, depending on the application, can vary between few tens of mV to 4.5V peak to peak - hence the reason for having a variable gain amplifier.
The output is then fed into a high speed peak detector to detect the amplitude and convert it into DC for a ADC.
I did think about shifting it but that would then introduce DC which could then reduce the ADC level to half (unless I add another stage - but because we have up to 42 channels it would impact the small board space available).
Any other suggestion? Or perhaps a refinement on your initial one?
Many thanks!!
