Datasheet

Page 7
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But all specs aren’t equal�
Many vendors claim an update rate specification, but that is
only in a special mode, or without any features turned on� Table
1 shows the 3000T X-Series’ update rate versus a competing
oscilloscope�
While all scopes update rate will vary to some degree by the
timebase setting, it is critical that the update rate remain
constant regardless of the functionality you are using within the
oscilloscope�
Table 1� Measured update rate between the 3000T
X-Series and the Danaher Tektronix MDO3000�
Note how the update rate fluctuates wildly on the
MDO3000 based on different settings/features�
10 ns/div
Keysight 3000T X-Series Tektronix MDO3000
Series
Update
rate
Probability Update
rate
Probability
Max with no
features on
1,114,000 94% 281,000 50%
Max with digital
ch on
1,101,000 94% 132 0.03%
Max with
measurements
on
1,114,000 94% 2,200 0.55%
Max with FFT on 1,114,000 94% 2,200 0.55%
Max with serial
on
1,100,000 94% 1,800 0.45%
Max with search
on
1,113,000 94% 2,200 0.55%
Max with ref
wfms on
1,113,000 94% 2,200 0.55%
Why is an uncompromised update rate important?
When debugging or troubleshooting a project, it is important
that you see as much signal detail as possible� A fast update rate
is just part of the overall equation to determine the likelihood of
seeing an anomaly� The frequency of the anomaly, the timebase
setting of the oscilloscope and the amount of time you allow the
oscilloscope to see the anomaly all come in to play:
Therefore, it is important to select an oscilloscope with the
fastest uncompromised update rate to allow enough time to
increase your chances of seeing the glitch� In Table 1, in addition
to the measured update rate, we show the probability of seeing
a glitch that happens 5 times a second while allowing the
oscilloscope to acquire for 5 seconds� With the 3000T X-Series
you maximize your chances of seeing the infrequent glitch� With
the competing scope, if you are using any of the other features
like measurements, or search or digital channels, the update rate
slows considerably� The only option you have in this case is to
allow the oscilloscope to run longer� For example, if you are using
digital channels you’ll have to let the scope run over 8,000 times
longer to get a similar probability to the uncompromised update
rate of the 3000T X-Series� That’s almost 12 hours of time versus
5 seconds!
P
t
= 100 x (1-[1-RW]
(U x t)
)
where
P
t
= Probability of capturing anomaly in “t” seconds
t = Observation time
U = Scope’s measured waveform update rate
R = Anomalous event occurance rate
W = Display acquisition window = Timebase setting x 10
Discover: The Industry’s Fastest Uncompromised Update Rate Increases the
Chance of Finding Anomalies (Continued)