Can I Self-Calibrate an SMU While the Load is Connected?

Issue Details

• I'm running Self-Calibration as part of my testing or calibration routine. However, I would like to avoid disconnecting the load from the SMU. Can I run Self-Calibration while the load is still connected?
• I'm running Self-Calibration in my SMU while the load or device under test (DUT) is still connected, and I am getting an Overload Protection (OLP) error. Is this expected? 

Solution

Running Self-Calibration while the load or DUT is still connected is not the correct process, and you may experience unexpected behaviors, for example an Overload Protection error. The calibration manual of the SMUs mentions that the Self-Calibration requires the DUT or load to be disconnected first. Even if there doesn't seem to be any issues with the Self-Calibration while the load is connected, this is not recommended. 

• The typical solution in this situation is to add an external dedicated switch to cleanly disconnect the SMU channel from the load or DUT. 

Additional Information

Disconnecting or disabling the output in the software is not a solution unfortunately, because Self-Calibration involves closing and opening different relays in the SMU, and it won't be as simple as using the software to disable or disconnect the output. As mentioned, an external dedicated switch is required.