Check Current Noise (20 Mhz - Keithley 2280 Series Reference Manual

Series 2280 Precision DC Power Supply Reference Manual

Check current noise (20 MHz)

Equipment required
Oscilloscope
Electronic Load
BNC F-to-Banana
To check current noise (20 MHz):
1. Plug the device under test (DUT) into your local line power from the mains.
2. Plug the test oscilloscope into the same mains outlet as the DUT.
Some AC power sources create large amounts of high frequency noise on the power line that the
instrument may not fully reject. Noise directly on the mains is typically better controlled.
Use the same mains outlet for both the DUT and test oscilloscope to avoid ground loops which may
cause noise.
3. Power on the DUT and test oscilloscope.
4. Set up the equipment as described in
5. Set the oscilloscope as follows:

1 mV/division
 1 MΩ input resistance

20 MHz bandwidth limit

AC coupled

Autotrigger

1 ms/div

Set to measure V
6. Set the DUT to the 100% full-scale output voltage.
7. Set the DUT to the 100% full-scale output current.
8. Turn the DUT output on.
9. Set the electronic load R mode (1 Ω).
10. Enter the oscilloscope measurements in the
checking noise at 20 MHz.
077085503 / March 2019
Check voltage noise (20 MHz)
RMS
High current 18 AWG wire
Coaxial cable (BNC M-M)
(on page B-38).
Current noise at 20 MHz
Appendix B: Verification
(on page B-16) table for
B-41