Digital In-Circuit Test
The digital in-circuit test describes the application of the in-circuit testing in the digital range. When the operating voltage is applied, digital signals are impressed into the inputs of the individual components of a module (backdriving) and the outputs are checked. As with the guarding techniques in the analog in-circuit test, digital ICT uses "digital guarding", i.e. additional fixture pins are used, for example, to switch inactive devices that interfere with feeding signals into bus lines, or feedback loops in a circuit are interrupted. Certain design for testability (DFT) measures are required when using ICT.