Error 5111 on Keithley 2461 · Tektronix Community

Hi, We are new to 2461 coming from 2430.  We are encountering 2 issues: 1. We are trying to setup a pulse measurement for a pulse width of 250us at 2% duty cycle at a force current of 2.7A.  However, when we try to generate, it displays Error 5111.  We play around with different timing (such as pw=4ms, offtime=12.5ms, at source current of 1A) and it can generate (see img1).  As per manual, the minimum pulse width is 150us.  Sometimes even if we set at 50% duty cycle at 12.5ms pulse width, were still getting Error 5111.  What is the proper way to setup pulse measurements and get discrete values on the screen (not using Digitize or turning Acquire measurements off)? 2. We are measuring BVdss of a MOSFET and sourcing 250uA (non-pulsed).  We are getting the correct reading of the breakdown voltage.  However, the meter display is not showing the 250uA Source current (see img2).  What is happening here? TIA

For topic #2, check the state of your interlock.  I suspect that is not engaged and it is normal for the instrument to clamp the output below ~42V.  In your case, you are hitting the voltage clamp level and so the current forcing is not the primary action of the SMU any longer;  the actual current will be the clamped V / DUT R. For topic #1, error 5111 is because the measure time will exceed the requested pulse width. Try setting the NPLC to minimum of 0.01 which for 60Hz power equates to 166.7usec. Make sure you turn off the source readback;  that defaults to ON which means two measurements occur (one for V and one for I) which at 0.01 NPLC puts you past the 250usec pulse width.  Turn it off so that if forcing I, it only measures V and does not also read back the source level. Source or Measure Delays could also be playing a role;  set them to zero. Last:  make sure your firmware level is up to date.  1.7.12b is current release.