A source-measure unit (SMU) provides an efficient way to apply precision stimulus to a device under test while simultaneously accurately measuring the DUT response. SMUs are suitable for a variety of applications, including semiconductor device characterization.
In a paper posted on the PXI Systems Alliance website, National Instruments explains how to use its new NI PXIe-4139 SMUs, introduced at DesignCon in January, to measure the power efficiency of a Texas Instruments TPS54360 step-down converter over a wide I/V range.
The paper also describes how to use the instrument's pulse mode to characterize a CREE LED with a 37-V forward voltage—beyond the 20-VDC range of the instrument. In addition to enabling the measurement, the pulse capability minimizes heat dissipation in the DUT.