Agilent Technologies E3640A - Diagram of Common Mode and Normal Mode Sources of Noise

Chapter 7 Tutorial
Output Characteristics
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Figure 7-6. Simplified Diagram of Common Mode and Normal Mode
Sources of Noise
When the load changes very rapidly, as when a relay contact is closed, the
inductance in the hook up wire and in the power supply output will cause a
spike to appear at the load. The spike is a function of the rate of change of the
load current. When very rapid changes in load are expected, a capacitor with
a low series resistance, in parallel with the power supply, and close to the load
is the best way to minimize these voltage spikes.
OUTPUT
TERMINAL
OUTPUT
VOLTAGE
COMMON
MODE
NOISE
<1.5 uArms
NORMAL
MODE
NOISE
R
<5mVpp*
<0.5mVrms*
<8mVpp**
<1mVrms**
*E3640A/41A/44A models
**E3641A/43A/45A models