Ground lead inductance
Ground lead inductance
When you touch your probe tip to a circuit element, you are introducing a new resistance, capacitance, and inductance into the
circuit.
You can determine if ground lead effects may
be a problem in your application if you know
the self-inductance (L) and capacitance (C)
of your probe and ground lead. Calculate the
approximate resonant frequency (f
0
) at which
this parasitic circuit will resonate with the
following formula:
The equation shows that reducing the ground
lead inductance will raise the resonant
frequency. If your measurements are affected
by ringing, your goal is to lower the inductance
of your ground path until the resulting resonant
frequency is well above the frequency of your
measurements.
The low-inductance ground contacts described
in
Accessories
can help you reduce the
effects of ground lead inductance on your
measurements.
TAP2500, TAP3500, and TAP4000 Instruction Manual
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