Figure 10.28:
Spread spectrum clocking profiles.
Chapter 11:
High-Speed Measurement Techniques
Figure 11.1:
Illustrative example of flight time (T
prop
) showing flight time as function of
voltage threshold.
Figure 11.2:
Example of oscilloscope bandwidth limiting resulting in an error of
measured clock to data skew. (a) actual signals; (b) measured on oscilloscope.
Figure 11.3:
(a) Inadequate real-time sampling. (b) A random delayed trigger of a
repetitive signal can be used to reconstruct the waveform in equivalent time. (c) A
voltage glitch can be missed altogether if the maximum sampling rate is wider than the
glitch.
Figure 11.4:
How measurement resolution loss occurs when the sampling rate is
inadequate.
Figure 11.5:
Vertical resolution loss due to inadequate sampling of high-frequency signal.
Figure 11.6:
The probability distribution can be used to incorporate the effects of jitter on
rise time.
Figure 11.7:
Simplified example of a current-source TDR output stage, including
sampling input to oscilloscope.
Figure 11.8:
Basic example of TDR response as seen at node A for test conditions. The
response illustrates the voltage and time relationship as the pulse propagates to
termination.
Figure 11.9:
Simplified response illustrating the TDR response effect to capacitive and
inductive loading along a 50-
line.
Figure 11.10:
Typical lumped element response characteristics: (a) TDR input; (b)
lumped element; and (c) response.
Figure 11.11:
TDR pulse characteristics that affect measurement resolution.
Figure 11.12:
Cross-section view of two different PCB boards connected by a typical
connector along with the simple model.
Figure 11.13:
The TDR response for two different edge rates illustrates the resolution
difference on the connector lumped elements.
Figure 11.14:
Example of how the incident pulse characteristics will be replicated.
Figure 11.15:
Examples of different hand-held type probes with varying ground loops.
Figure 11.16:
This illustrates a typical TDR response difference between two different
handheld probes with different ground loops.
Figure 11.17:
Lattice diagram of multiple discontinuities, resulting in the superposition of
reflections.
Figure 11.18:
Basic test setup for accurate impedance measurements using an airline
reference standard.