
ZD Series High Impedance Differential Probes
8
Probe Input Loading
Attaching any probe to a test circuit adds some loading to the circuit under test.
In most applications, the high impedance of the probe, compared to the
impedance of the circuit under test, imparts an insignificant load to the test
circuit. However, at very high frequencies the capacitive reactance of the probe
tip or lead may load the circuit enough to affect the measurement. The ZD
series probes are designed to minimize these effects at high frequencies. Refer
to the figures below for differential input equivalent circuit and impedance vs.
frequency derating.
ZDxxxx Differential Input Equivalent Circuit