Product data

Why does a fast update rate matter?

While bandwidth, sample rate and memory depth are key criteria

for deciding which scope to purchase, an equally important char-

acteristic is update rate.

What is update rate?

Update rate is how many waveforms acquisitions per seconds

you scope can acquire, process, and display. Oscilloscope “dead-

time” is the time it takes for a scope to process and then display

an acquired waveform before re-arming it’s triggering for the next

acquisition. For traditional scopes, this time is often orders of

magnitude greater than acquisition time on fast time-per-division

settings.

If a glitch occurs during the scope’s dead-time, it won’t be

captured. The key to improving the probability of capturing a

signal anomaly during the scope acquisition time is to minimize

dead-time.

Oscilloscope vendors usually specify what their scope’s “best-

case” waveform update rates are. Some scope architectures

suffer from factors that can seriously degrade the “best-case”

update rates spec. Agilent’s 6000 Series architecture delivers the

world’s fastest update rate when using:

•

Analog channels

•

Analog and digital

•

Deep memory

•

Serial decode

Why is update rate important?

1. Responsiveness. If you rotate the timebase control, you ex-

pect the oscilloscope to respond immediately – not seconds

later after the scope ﬁ nishes processing data.

2. Signal detail. Fast waveform update rates improve the

display quality of the waveform that you see on screen.

3. Certainty. Fast waveform update rates improve the scope’s

probability of capturing random and infrequent events.

Update rates directly affect a scope probability of capturing and

displaying infrequent and random events. Slow update rates will

cause a scope to miss subtle or infrequent signal details.

Improves instrument responsiveness

Improves scope display quality

Improves probability of capturing

infrequent events