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.
16
TPR1000 and TPR4000 User Manual
