Connecting PXIe-4137 in parallel for higher current

[emks25]

Hello.

I've read from NI's articles that it is possible to connect SMU instruments in parallel for higher current. My test requires 20V and 2A, so I was thinking of connecting two PXIe-4137 channels in parallel to supply the needed 2A. However, I am concerned about the fact that I am forcing both channels at their highest possible current.

May I know if there are any best practices for connecting SMU instruments in parallel? Additionally, what are the issues I may encounter if I use such a configuration and force both instruments at their highest current rating?

[santo_13]

What kind of load are you connecting at the outputs?

do you plan to use both SMUs in Source Voltage?

have you considered the inaccuracies in sourced voltage due to instrument differences?

You're at the verge of maximum possible current for each SMU, typically it is fine as the SMU specs already have some headroom. Since you tend to operate at the SMUs limit, if your external load try to consume 2A, the SMUs will switch to CC mode and actual voltage will be lower than configured - will this be a problem for your test?

I believe you read this article - https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000x22lCAA&l=en-IN

[emks25]

Hello. Upon examining the test more closely, we were able to verify that the 2A setting was just the current clamp that was set while 20V was forced by the resource. We have decided to simply use the PXIe-4139 channel as it has 40W DC supply capability. To make sure that there are no issues when it comes to pushing the resource to its limit, we decided to set the current limit to 1.5A instead of 2A.

Thank you for your help!