I have a question regarding the peak detector operation on the output of VGA1, which we are using as a control voltage for the input attenuator on VGA1.
The data sheet specifies for linear performance the output of VGA1 is 1.5v pk-pk differential. How does the peak detector work, does it look at the differential voltage or is it looking at the single ended voltage?
I have assumed that the detector is looking at the single ended peak voltage, so for a 1.5V pk-pk differential voltage this is 0.75V pk-pk single ended, which equals 0.375V peak. Having made some measurements I'm beginning to think that my assumption is wrong and its operating on the peak differential voltage, which is 0.75V peak for a 1.5V pk-pk differential voltage.