Dictionary of Electronics
"A" "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"

Device Under Test

Device Under Test. [DUT] The component, device or system under going testing. Normally the Device Under Test is a component that forms a larger unit or module, while Unit Under Test [UUT] is the unit or system under test. IC logic testing also includes the term Gate Under Test [GUT] to indicate a single gate being tested out of an IC containing a number of logic gates.
Note that System Under Test [SUT] is also in common usage as an acronym. Additional System Test Acronyms.

Transistor Under Test
BJT Device Under Test

The schematic depicts a power output test circuit for a 2N3866 transistor. The transistor is the Device Under Test [DUT], or Unit Under Test [UUT]. A completely different circuit would be used to test Rise Times or Fall Times, to name just a few examples of transistor parameters.

Additional DUT circuits are provided on the next page;
Transistors DUT Circuits.
Power Derating Curves for NPN Transistors
Different types of components would require different tests and completely different setups. A 741 DUT setup is shown lower down the page.

Any Device Under Test will require an input stimulus for the device or unit to provide a response that is then measured against the input. The input stimulus could be temperature changes [heat or cold], or voltage or power inputs, what ever the unit is being tested for. The resulted output is then checked against the test procedure to determine if the unit has passed or failed the test.
The measurement or calibration that compares a DUT to a standard or reference is called the Test Uncertainty Ratio [TUR].

In many cases custom burn-in Printed Wiring Boards [PWB] or DUT boards are produced so that individual components or circuits may be tested and measured while attached to the board. The burn-in boards provide mounting for the components under test and connection points for instrumentation to measure the different points of the circuit under test. DUT Boards may also be used to simulate the interaction of the components and the circuits attached to the board.

Device-Under-Test Boards may also be called Load Boards, and in the case of Automatic Test Equipment [ATE] being utilized called ATE Interface Boards. However there is no requirement to use Automatic Test Equipment, any test may be run manually or may be automated.

Of course the purpose of any test board is to hold the DUT and any Input/Output I/O interfaces as required, but so to not introduce any noise, distortion or any thing else that would tend to off-set or change the results of the test. In addition the wires used for measurement should not introduce any un-wanted capacitance or increased resistance.

More often then not DUT boards are custom boards because they need to hold the components under test and carry the correct fixtures for the test equipment being used.

Another term in usage is Interface Test Unit [ITU] which would also refer to a DUT Board. The Interface Test Unit is the interface [PWB] between the Device Under Test and the Test Equipment.
Related; IC Converter and Adaptor Manufacturers

If certification of the test is required the test equipment and DUT Board may be required to meet certain requirements for test certification
Related; Compliance Testing

In specific cases the term Transistor Under Test or TUT may be seen used on military specifications. Example schematic using the term TUT; Transistor Circuits

741 Device Under Test
741 Under Test
741 OpAmp Device Under Test

Details for the circuit setup are provided on the right side of the page. Set-up note; this configuration should work for either the 00C to 700C range or -550C to 1250C range. Technical note; the supply ranges depend on the actual device used but should be around +/- 22 volts.

Operational Amplifier Under Test
OpAmp Device Under Test

This Op-Amp circuit uses less power supply bypassing than the previous circuit example, but does use input compensation.

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference