7Tutorial
354 Keysight 33210A User’s Guide
Ground Loops
The signal-generation portion of the Keysight 33210A is isolated from chassis
(earth) ground. This isolation helps to eliminate ground loops in your system and
also allows you to reference the output signal to voltages other than ground. The
illustration below shows the function generator connected to a load through a
coaxial cable. Any difference in ground potentials (V
GND
) will tend to make current
I
GND
flow in the shield of the cable, thus causing a voltage drop due to the shield's
impedance (Z
Shield
). The resulting voltage drop (I
GND
× Z
Shield
) appears as an error
in the load voltage. However, since the instrument is isolated, there is a high
series impedance (typically 1 MΩ in parallel with 45 nF) in the path to oppose the
flow of I
GND
and thereby minimize this effect.
Ground Loop Effects
Keysight 33210A
50W
V
GEN
R
L
V
L
= V
OUT
– (I
GND
× Z
Shield
)
V
OUT
Z
Shield
1 MW
I
GND
V
GND
45 nF
To Next Page
Loading...
