Atec Agilent-346a - Manual (Page 26)

26
Designing and Probing with Target Connections
For All Agilent Logic Analyzers with 40-pin Pod Connectors
Equivalent Probe Loads
The following probe load
models are based on in-circuit
measurements made with an
Agilent 8753E 6 GHz network
analyzer and an Agilent 54750A
TDR/TDT using a 50
Ω test
fixture. The following schematic
accurately models the probe load
out to 6 GHz.
Rtap
400 Ω
Din
Cstub
0.375 pF
Rtip
100 K
Ω
Ctip
10 pF
Rtip1
250 Ω
Lspring2
1.17 nH
Lspring1 Din
0.63 nH
Cstub
0.375 pF
Rgnd1
10
Ω
Ccoupling
0.070 pF
Rtip2
100 K
Ω
Ctip
10 pF
Rgnd2
120
Ω
Figure 5.14. Simple (does not include capacitive
coupling between channels or inductance of the
spring pins)
Figure 5.15. Complex (includes capacitive coupling between channels and inductance
of spring pins)