Tektronix P6450, Инструкция по эксплуатации

Страница: 36 / 51

Reference
Transmission Lines.
Due to the high performance nature of the interconnect,
ensure that stubs, which are greater than 1/4 length of the signal rise time, are
modeled as transmission lines.
P6450 Probe Load Model.
The following electrical model includes a
low-frequency model of the High-Density Single-Ended Probe. (See Figure 15.)
Figure 15: High-Density probe load model
Probe Footprint Dimensions
Use the probe footprint dimensions to lay out your circuit board pads and holes
for attaching the retention posts. (See Figure 16 on page 21.) If you are using the
alternate retention assembly, all dimensions remain the same as shown below,
except the overall length and width. (See Figure 10 on page 17.) Pad
fi nishes that
are supported include immersion gold, immersion silver, and hot air solder level.
All dimensions are per standard IPC tolerance, which is ±0.004 in.
NOTE.
Tektronix recommends using immersion gold surface fi nish for best
performance.
Tektronix also recommends that the probe attachment holes
fl oat or remain
unconnected to a ground plane. This prevents overheating the ground plane
and promotes quicker soldering of the retention posts to your PCB. The probe
retention posts are designed to allow you to solder the retention posts from either
side of your PCB.
20 P6450 High-Density Logic Analyzer Probe Instruction Manual