33 | Keysight | Probing Solutions for Logic Analyzers - Data Sheet
Probing Solutions for 90-pin Logic Analyzers
Soft Touch Connectorless Probing (Continued)
Equivalent probe loads
The following probe load models are based on in-circuit measurements made with a
Keysight 8753E 6 GHz network analyzer and a Keysight 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
D1
L11
L12
Rtip1
20 K
0.63 nH
1.17 nH
Rtrm1
75
C12
0.280 pF
+0.75 V
Cm12
0.070 pF
Rgnd1
0.5
Cshnt2
.350 pF
Rtip2
D0
L21
L22
0.63 nH
C22
1.17 nH
20 K
Rtrm2
75
0.280 pF
+0.75 V
Rgnd2
0.5
Figure 4.26. Equivalent probe load model.