Atec Agilent-346a - Manual (Page 56)

56
Designing and Probing with Target Connections
Agilent Logic Analyzers with 90-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. PC board pads are
not included.
Cshnt1
.350 pF
Rtip1
20 K Ω
Cshnt2
.350 pF
Rtip2
20 K Ω
L12
1.17 nH
L22
1.17 nH
L11
0.63 nH
L21
D1
D0
0.63 nH
Rtrm1
75
Ω
C12
0.280 pF
Rgnd1
0.5
Ω
C22
0.280 pF
Rgnd2
0.5
Ω
Cm12
0.070 pF
+0.75 V
Rtrm2
75
Ω
+0.75 V
Figure 8.17. Equivalent probe load model