General-Purpose Probing System Description - Agilent Technologies HP 1660E Series User Manual

Logic Analyzer Reference
Probing

General-purpose probing system description

The standard probing system provided with the logic analyzer consists
of a probe tip assembly, probe cable, and grabbers. Because of the
passive design of the probes, there are no active circuits at the outer
end of the cable. The rest of this chapter is dedicated to general-
purpose probing.
The passive probing system is similar to the probing system used with
high-frequency oscilloscopes. It consists of a series RC network (90 kW
in parallel with 8 pF) at the probe tip, and a shielded, resistive
transmission line. The advantages of this system include the following:
• 250 W in series with 8-pF input capacitance at the probe tip for minimal
loading
• Signal ground at the probe tip for high-speed timing signals
• Inexpensive, removable probe tip assemblies
Probe Tip Assemblies
Probe tip assemblies lets you connect the logic analyzer directly to the
target system. This general-purpose probing is useful for discrete
digital circuits. Each probe tip assembly contains 16 probe leads (data
channels), 1 clock lead, a pod ground lead, and a ground tap for each of
the 16 probe leads.
Probe Tip Assembly
261