source measure unit (SMU)
A Source Measure Unit (SMU) is a combination of a meter and a precise power supply. Conventional multimeters can measure the current and voltage of a device under test( DUT). Since several measuring devices with different properties and characteristic values can be connected during measurements, consistent, precise measurements are only possible to a limited extent.
The situation is different with a Source Measure Unit (SMU), which is equipped with precise voltage and current supplies and can thus supply the DUT. Functionally, an SMU unit consists of a laboratory power supply with two supply units, a regulated precision voltage and current source. Measurement-wise, it performs the functions of a digital multimeter for high-precision current and voltage measurements.
Depending on the test task, one or the other supply source is used. Like other meters, SMU units are equipped with automatic range switching and overcurrent and overvoltage protection. Thanks to Guard technology, currents can be measured down to the femto- ampere range.
Source Measure Units are used in functional testing and in-circuit testing. Furthermore in material research, testing of semiconductor devices, power semiconductors and electronic circuits.