SMU to sink current

[Pranay_c]

Hi,

I am using NI PXIe-4139 to sink current from a converter(i.e., to make it behave as a load). I have configured SMU to Constant Current mode and gave the current value as -3A, so that SMU can operate in 4th Quadrant and sink current. 

But the SMU is not sinking the exact desired value from the convertor. I am attaching the circuit connection diagram which I used, please help me in finding the exact way to sink current using an SMU.

[crossrulz]

What converter are you trying to test?  Exactly how much current are you sinking?  Does it work properly at a lower current?  Can the converter even output 3A?

[Pranay_c]

hi crossrulz, I am trying to sink 3A from the converter and it has capability to deliver 3A.

[cstorey]

What's the voltage this converter supplies at 3A?  Here's the quadrant diagram for the PXI-4139, not that at -3A you are limited to -6.6V to +4V.  So the SMU is limited to 20W (12W).  If you've converter needs to supply more voltage to hit the 3A limit then that's your problem.  This is my pet peeve with SMUs, as all manufacturers advertise -3A/+-60V but those two limits don't go together and you have to look very carefully at these source-sink diagrams.

[Pranay_c]

Hi cstorey,

The Converter which i am using is configured to deliver a constant voltage of 1.6V provided input is in range of 2.25 to 5.5V.

[Khushbu_K]

Hi,

We are facing the same problem. Did you get solution for your query?

[santo_13]

@Khushbu_k, please create a separate post with a detailed description of your query. Please include complete details of the connections and source code.