Cyclic noise was found from B2902A SMU. Connecting a Si SBD 1N5822 to B2902A SMU in 2-wire mode (connecting to the two force terminals) and observing the terminal voltage using TDS220 oscilloscope, I found cyclic noise of 70mVp-p in every 375ms. What is the origin of this noise? When I short-curcuited the input terminal of TDS220, no noise was found. The cyclic noise was only found after waking up of B2902. I attached a photo of TDS220.
I would like to know the origin of the noise and the setting for avoiding this phenomena.