Agilent Technologies B1500A Training Manual page 91

High Voltage SPGU
Effects of Load Impedance
Mismatch of load impedance
setting may cause the error of
applied voltage to the DUT.
Setup: 1V output, 50 Ω load
Actual load: 1 MΩ
Setup: 1 V output, 1 MΩ load
Actual load: 50 Ω
Here is the example of the voltage error due to the mismatch of the load impedance setting.
If the load impedance is set to 50 ohm when the actual load impedance is 1 Mohm, the voltage actually applied
to the DUT is about double the setting value. If the load impedance is set to 1 Mohm when the actual load
impedance is 50 ohm, the voltage actually applied to the DUT is about half the setting value. So the load
impedance value must be accurate to apply the voltage near the setting value to the DUT.
2 V output
0.5 V output
13-7
SPGU Control and Applications
Actual
Expected
Expected
Actual
Module 13