330
6000 Series Oscilloscope User’s Guide
8
Reference
Figure 51
Impedance versus Frequency for Both Probe Circuit Models
The logic probes are represented by the high-frequency circuit
model shown above. They are designed to provide as much
series tip resistance as possible. Stray tip capacitance to ground
is minimized by the proper mechanical design of the probe tip
assembly. This provides the maximum input impedance at high
frequencies.
Probe Grounding
A probe ground is the low-impedance path for current to return
to the source from the probe. Increased length in this path will,
at high frequencies, create large common mode voltages at the
probe input. The voltage generated behaves as if this path were
an inductor according to the equation:
Increasing the ground inductance (
L
), increasing the current
(
di
) or decreasing the transition time (
dt
), will all result in
increasing the voltage (
V
). When this voltage exceeds the
threshold voltage defined in the oscilloscope, a false data
measurement will occur.
100 k
Ω
10 k
Ω
1 k
Ω
100
Ω
10
Ω
1
Ω
10 kHz
100 kHz
1 MHz
10 MHz
100 MHz
1 GHz
High
Frequency
Model
Typical
Model
Frequency
Impedance
V
L
di
dt
-----
=
Summary of Contents for InfiniiVision DSO6014L
Page 2: ...Agilent Technologies Agilent 6000 Series Oscilloscopes User s Guide...
Page 59: ...58 6000 Series Oscilloscope User s Guide 1 Getting Started...
Page 109: ...108 6000 Series Oscilloscope User s Guide 2 Front Panel Controls...
Page 125: ...124 6000 Series Oscilloscope User s Guide 3 Viewing and Measuring Digital Signals...
Page 251: ...250 6000 Series Oscilloscope User s Guide 5 Making Measurements...
Page 287: ...286 6000 Series Oscilloscope User s Guide 6 Displaying Data Interpreting Decoded LIN Data...
Page 321: ...320 6000 Series Oscilloscope User s Guide 7 Saving and Printing Data...
Page 370: ......
