Does anyone know how much dead time the current digital scopes have in xy mode?
AFAIK modern xy mode is a spin-off of the digital phosphor technology. Many digital scopes even keep the trigger activated in XY-mode. This means, each time the trigger is activated, a snapshot of the signal on X and Y is taken and summarized to the display matrix.
But this also means that the time between the snapshots is just plotted to the screen.
In the end we have (at least) three main differences comparing analogue to digital:
- Analogue is without any dead time. XY-mode does not even need an electron beam return blank.
- Analogue has no latency or display update rate
- Analogue has no quantisation effects reducing the available resolution
Is there any modern digital scope that really addresses all these issues? At least for lower bandwidths I could imagine a continuos, triggerless data acquisition like in roll-mode. Display update rate is a matter of computing power and the relevance of quantisation is a matter of available memory - so very theoretically it may be possible, but did anyone do it?