Device under test also known as unit under test (UUT), is a term commonly used to refer to a manufactured product undergoing testing.

In semiconductor testing

In semiconductor testing, DUT refers to a specific die

Die (integrated circuit)

A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...

 on a wafer

Wafer (electronics)

A wafer is a thin slice of semiconductor material, such as a silicon crystal, used in the fabrication of integrated circuits and other microdevices...

 or the resulting packaged part. Using a connection system, the part is connected to a piece of manual

Semiconductor curve tracer

A semiconductor curve tracer is a specialised piece of electronic test equipment used to analyse the characteristics of discrete semiconductor devices such as diodes, transistors, and thyristors...

 or automatic test equipment

Automatic test equipment

Automatic or Automated Test Equipment is any apparatus that performs tests on a device, known as the Device Under Test , using automation to quickly perform measurements and evaluate the test results...

 (ATE). The ATE then applies power to the part, supplies stimulus signals, then measures and evaluates the resulting outputs from the device. In this way, the ATE determines whether the particular device under test is good or bad.

While in the form of a wafer, the ATE connects to the individual DUTs (dice) using a set of microscopic needles. Once the chips are sawn apart and packaged, the ATE connects to the DUTs (packages) using ZIF sockets (sometimes called contactors).

General electronic testing

The term DUT is also used more generally within electronics to refer to any electronic assembly under test. For example, cell phones coming off of an assembly line may be given a final test in the same way as the individual chips were earlier tested. Each cell phone under test is, briefly, the DUT.

The DUT is often connected to the ATE using a bed of nails tester of pogo pin

Pogo pin

A Pogo pin is a device used in electronics to establish a connection between two printed circuit boards. Named by analogy with the pogo stick toy, the pogo pin usually takes the form of a slender cylinder containing two sharp, spring-loaded pins...

s.