Ultra-fast I-V sourcing and measurement have become increasingly important capabilities for many technologies, including compound semiconductors, medium power devices, non-volatile memory, MEMs, nanodevices, solar cells, and CMOS devices. Using pulsed I-V signals to characterize devices rather than DC signals makes it possible to study or reduce the effects of selfheating or to minimize current drifting in measurements due to trapped charge. The Model 4225-PMU Ultra-Fast I-V Module for the Model 4200- SCS Semiconductor Characterization System supports many of these high speed source/measure applications.