Tektronix MSO70000C/DX Technical Reference page 65

Horizontal and acquisition system (cont.)
series)
Timebase stability (sample rate
jitter or jitter noise floor), typical
<4 GHz models
Timebase jitter with external
reference, typical, ≥4 GHz models
Delta time measurement
accuracy, >20 GHz models
MSO70000C/DX, DPO70000C/DX, DPO7000C, MSO5000/B, DPO5000/B Series
Specifications (MSO70000C/DX, DPO70000C/DX, and DPO7000C
Total:
<1.0 ps rms for record durations less than 10 μs
<2.5 ps rms for record durations less than 30 ms
<65 parts/trillion for record durations less than 10 s
≤3 ps at 100 ms delay
RMS
The formula to calculate the maximum delta-time measurement accuracy (DTAmax) for a given
instrument setting and input signal is given below (assumes insignificant signal content above
Nyquist and insignificant error due to aliasing, overdrive recovery and overdrive interpolation):
N = typical input-referred noise spec (volts rms)
typ
F = 1.3 for instrument bandwidth ≤9 GHz; 1.5 for instrument bandwidth ≥10 GHz
N
SR = slew rate around 1st point in measurement (1st edge)
1
SR = slew rate around 2nd point in measurement (2nd edge)
2
TBA = timebase accuracy (2 ppm)
F = 1.2 × 10–2
I
r1
t = rise time of first edge
r
t = rise time of second edge
2
t = sample jitter/aperture uncertainty (about 250 fs for time durations less than 10 μs)
j
t = delta-time measurement (seconds)
reading
Peak-peak based on statistical accumulation of 1000 waveforms.
DTA = 10 × (N × F
MAX pk-pk typ
TBA × t
RMS is guaranteed regardless of data-gathering duration.
DTA = 10 × (N × F
MAX RMS typ
TBA × t
The term under the square-root sign is the stability and is due to time interval error (TIE). The
errors due to this term occur throughout a single-shot measurement. The second term is due to
both the absolute center-frequency accuracy and the center-frequency stability of the timebase and
varies between multiple single-shot measurements over the observation interval (the amount of
time from the first single-shot measurement to the final single-shot measurement). The observation
interval may not exceed 1 year.
Test at maximum bandwidth.
( ) ( )
(
1 2 1 2
2
2
) + + F ×
N I
SR SR
1 2
seconds
reading pk-pk
( ) ( )
(
1 2 1 2
2
2
) + + F ×
N I
SR SR
1 2
seconds
reading RMS
)
2 2
2
t + t + (2 × t ) +
r1 r2 j
)
2 2
2
t + t + (2 × t ) +
r1 r2 j
53