Low Side of SMU current

[matthewself12]

This a more general question from a noob to SMUs. I was wondering if the PXI SMUs pull/push current on the low-side reference connection?

Situation: I want to set the low side of the SMU (both force and sense connection together) to 0V or 5V (depending on situation). When I set the low reference, does the SMU FL pull much current, if any at all? I am looking to use a 20mA DIO to set the reference, so can't have it pulling more than this. The high side of the SMU is a different situation in this case and doesn't have strict current limitations. Thanks.

[santo_13]

What SMU model are you talking about?

Typically SMUs work in 4 quadrants. In a 4-quadrant use case, yes, the polarity of HI will change with respect to LO to change based on the quadrant.

You don't specify what is the voltage at LO instead you specify what should be the voltage at HI with respect to LO.

[matthewself12]

I believe the model is a PXIe-4135, which is a 4-quadrant SMU.

If I bias the low side to 5V and then tell the SMU to force high 10V, I would expect to have 15V differential to GND on the high side. My question is how much current is actually being used to bias the SMU low-side to 5V, if that makes sense. Again, I am very new to this, but want to make sure that my low bias is not pulling much current without any external resistance.