qutools quTAG MC - Jitter Measurement Explained

www.qutools.com quTAG MC Manual 5
• High energy/accelerator physics
• High precision time measurements
Channels input
1 Start / 8, 16, 32 Stop
Bin width
1 ps
Timing jitter – RMS, FWHM
20 ps, 50 ps
Input pulse high level
-5.0 V ... + 3.5 V
Input Impedance
50 Ohm
1.3 Jitter Measurement
In order to measure the jitter, we generate an electrical pulse with steep edges. This pulse gets
split into two by a power splitter and sent into two different inputs of the quTAG (i.e. start and
stop-X or stop-X and stop-Y). Then we use the quTAG software to generate a start-stop-
histogram.
We fit a Gaussian function to this histogram and determine RMS and FWHM. The single
channel jitter corresponds to σ / √2 from this two-channel measurement, assuming equal
Gaussian contributions from both signals. The FWHM can be obtained by the standard
deviation with the relation FWHM = 2 √2 ln 2 σ ≈ 2.35 σ.