Isolate DC voltage spikes

When testing semiconductor devices, you often need to measure drain current or leakage current as a function of voltage. A DC voltage source and a DMM can easily make these measurements under computer control. But many voltage sources will produce spikes when you switch their output values. Fortunately, you can run a simple test to determine the accuracy of your voltage source as it changes values during a voltage sweep.

Transconductance measurements can reveal spikes in drain current lnked to spikes in source voltage.

To learn more tips and tricks for DC measurements, download a paper by Lee Stauffer of Keithley instruments at www.tmworld.com/voltage.