# How to route current for ATE?

I have many test points on a board, a small DAQ, and an SMU that I can program with LabView. Depending on the test, I need to change which test point the SMU is sending/measuring voltage or current.

To do this, I figured I should use a series of analog switches, and control the switch paths by using the DAQ's few outputs. (Eg. Outputting the high/low binary 000 sends the signal to the first test point TP1; 001 routes the SMU to TP2, etc.)

However, some of the tests I'm automating require sourcing/sinking up to 500mA of current from the SMU to the test point, and most switches advertise their "high-current capacity" of 150mA or so. Additionally, my SMU signal reaches a maximum of 20V at times, so it needs to be able to handle both.

I find it hard to believe that there isn't a switch that can do what I need, so what should I be searching for?

Is this usually how this kind of task is accomplished, or is there an alternative to switches that would be better?

• Welcome. If the test points are isolated, could they have independent loads? Or does each input have optional loads? Please clarify. – Sparky256 Jul 10 at 21:20
• Sorry, I'm not sure what you mean by "optional loads". The board that I'm testing has a bunch of circuit paths between the test points and GND, so I'm typically taking measurements of voltage or impedance from TP## to GND, while optionally (depending on the test) sinking/sourcing current to the same (or different) test point to GND. But I believe they are all part of the same circuit. I'm not super experienced so if my response doesn't answer your question, could you elaborate what you mean? – Alex G Jul 10 at 21:57