Source Measure Units

Source measure units combine a precision power supply and a high-resolution meter in one instrument, sourcing voltage while measuring current or the reverse, all within a single feedback loop.

Keithley, Keysight and Instek cover this range. This architecture is what makes semiconductor and materials characterisation practical, because sweeping a voltage and capturing picoamp-level current on the same instrument avoids the timing and grounding problems of a separate supply and meter. Four-quadrant operation lets the unit sink as well as source, which is required for battery and solar cell work. The specifications that matter are current measurement floor, voltage compliance and how quickly the unit settles between sweep points.