Voltage Spikes on PXIe-4141

Updated Dec 4, 2019

Reported In

Hardware

  • PXIe-4141

Issue Details

I am getting noticeable voltage spikes on the PXIe-4141 SMU. Is this normal? How can I avoid them? An example is displayed in the image below.


Solution

This is a result of the board's switching power supply, which is generating those spikes. It is the expected behavior of the device, but it is difficult in some cases to have accurate measurements. To avoid this, you have to use a filter and a common ground at the output of the SMU. The schematic of the filter is displayed below: 



The results with the connected filter and the common ground are displayed below: 



The only drawback of this solution is the expected output will be different because of the filter that is being used, so the input value should be slightly recalculated in respect to the filter to get the expected output value.