Long capture times give you better visibility into cause-effect relationships in your design, which greatly simplifies root-cause debugging. It also allows you to capture start-up events in a single acquisition. You dont have to stitch together multiple acquisitions or set precise triggering conditions. Spend less time finding events, and more time analyzing them.
The relationship between memory depth and acquisition rate isnt as obvious. All scopes have a banner maximum sample rate specification, but many can only sustain these rates at a few timebase settings. 5 GSa/s acquisition rate and 10-Kpts of memory, those 10,000 points can only fill 2 s of time. Since scopes have 10 time divisions, the sample rate drops at any time/div setting below 200 ns/div. As a result, if you look at slow/fast events like a modulated signal, you run the risk of aliasing your signal. Or you may simply miss out on important signal details when you zoom in on it.
Deep memory oscilloscopes let you sustain a high sample rate over longer periods of time.
MegaZoom III is the third generation of the fast and deep memory architecture that Agilent introduced in 1996. Its not a special mode, unlike other deepmemory oscilloscopes. You have access to your MegaZoom memory at all times. And the display will respond instantly to your commands as you scale the +/div setting or pan and zoom in the Delayed (or zoom) window.
If the human eye has trouble discerning above 30-50 frames per second, is there really a difference between 3,600 and 100,000 waveforms per second? If you know what youre looking for, the answer is probably no. However, if you are hunting for unknown signal anomalies or characterizing jitter, the answer is yes.
If you know that there is a glitch in your system, its easy to capture it using a pulse-width trigger. However, if you are just browsing through your design, your chances of finding a glitch increase as the oscilloscopes update rate increases. If a glitch occurs during the dead time between samples, you miss it. With MegaZoom III technology, the dead time is much smaller. A scope with a slower update rate will capture the glitch eventually (if it recurs), but most engineers and technicians dont have the time or patience to wait for their tools to catch up.
If you are characterizing signal jitter, a fast update rate gives you accurate results sooner. And when the fast update rate is combined with the 5000 Series XGA high-definition display (1024 x 768, 256 intensity levels), subtle differences in these acquisitions become obvious.
And like all other aspects of MegaZoom III technology, this update rate is delivered as a default real-time acquisition mode. Its always fast, always on.