Cv Ripple And Noise - Rigol DP831A Performance Verification Manual

Chapter 2 Constant Voltage Tests

CV Ripple and Noise

When the power supply is working in CV mode, the combination of the periodic and
random deviations (PARD) when outputting DC voltage is equivalent to
superimposing a residual AC voltage on the DC output voltage. This residual AC
voltage, namely the ripple and noise (usually, ripple is periodic offset while noise is
random offset), can be expressed in RMS or peak-to-peak value form.
DP831A is taken as an example to test the CV ripple and noise of DP800 series in the
following section.
Note: During the actual test, please select the corresponding test record form
according to the model of the DP800 power supply under test to set and select the
corresponding parameters, record and calculate the corresponding specifications.
Specification:
Ripple and Noise (20Hz-20MHz)
Normal Mode Voltage
Test Procedures:
1. Turn off DP800. Connect DP800, AC power supply, resistive load and
oscilloscope according to Figure 2-1. Both the resistive load and oscilloscope are
connected with the channel output terminals of DP800; please refer to "Test
Precautions" for the connection method. Here, CH1 is taken as an example
and the connection method is also applicable to CH2 and CH3.
Notes:
Do not connect the negative terminal of the output terminal of the channel

to be tested to the shielding ground; otherwise, a ground loop would be
formed. In Figure 2-3, the connection in figure A forms a ground loop while
figure B shows the correct connection.
DP800 Performance Verification Manual
<350μVrms/2mVpp
RIGOL
2-11