A fault diagnosis method of analog electronic circuits for mixed-signal systems controlled by microcontrollers

New methods of fault detection and localisation of analog parts in embedded mixed-signal microsystems controlled by microcontrollers is presented. The methods consist of three stages: a pre-testing stage of a fault dictionary creation. Next, a measurement stage based on the measurements of duration times of output signals of analog comparators realized by internal resources of the microcontroller. To the inputs of the comparators with different threshold voltages the time response to a stimulating square impulse of the analog part is applied. In the last stage the fault detection and localisation is performed by the microcontroller. The main advantage of the method is fact that the BIST consists only of analog comparators and internal resources of the microcontroller mounted in the system. Hence, this approach simplifies the structure and design of BISTs, which allows to decrease test costs