Uncertainties
Random Uncertainties (1
)
■ Quantization Error (E
q)
Eq = 65 ps rms
(<50 ps rms typical)
■ Start/Stop Trigger Error (Ess)
Eji
m
r = Single Period Jitter (rms) (s)
■ Trigger Level Timing Error (E
t
l)
Time Interval, Rise/Fall Time, Pulse Width,
Duty Factor, Phase (attenuator setting xl)
Sx = Slew rate at start trigger point (V/s) Sy =
Slew rate at stop trigger point (V/s) TLU =
Trigger level uncertainty (V) Hyst = Hysteresis
window (V)
Hyst = 30 mV ± 1% of trig lvl (DC to 1 kHz)
for Pulse Width & Duty Factor
Hyst = 6 mV ± 1 % of trig lvl (DC tol kHz) for
other measurement functions.
Example for phase with sinewave signals and 0
V trigger levels (attenuator setting xl):
, where
Vpk(A) = Inp A peak voltage in V, and
Vpk(B) = Inp B peak voltage in V.
TBE is the relative error of the timebase oscil-
lator (dimensionless) and depends on the actual
oscillator used. See Timebase Options on page
The general formula for all measurement
functions is:
Time Interval, Pulse Width,
Rise/Fall Time
■ Random Uncertainty (rms)
Etl = trigger level timing error
500 ps = maximum channel difference
TBE = timebase error
TIME = measurement result
8-40
USER MANUAL ● CNT 9x Series ● Rev.22 February 2020