In our application, the MSP-Gang is built into the board house test fixture. The MSP-Gang programs the board, and then testing is done to verify that the board is operating properly.
In previous verisons, we had used the MSP-Gang430, but since that is discontinued, we updated to the MSP-Gang. One of the tests is to measure the sleep current of the UUT (less than 15 uA).
We are powering the board during the test from the MSP-Gang (the MSP-Gang has an external PSU connected, not USB powered). The Vcc line is routed through a current measurement module (NI-9208), and then to the UUT. I am able to program and communicate with the UUT during the test, so the power is being applied to the UUT correctly. However, the current measurements are all over the place, and way more (100-200 uA) than the sleep current should be. Testing the UUT on a bench tester shows the correct sleep current.
Running the same boards on the MSP-Gang430, we get the correct sleep current. Looking over the schematics from the old programmer and the new one, it seems like the new MSP-Gang has a seperate supply chip for each target, where the old had one chip for all targets.
The COM on the NI-9208 is the same for all inputs, so there should be a common ground between the MSP-Gang and the NI-9208.
Am I getting some sort of feedback from the other circuits?
