Built-in dynamic current sensor for hard-to-detect faults in mixed-signal ICs

There are some types of faults in analogue and mixed signal circuits which are very difficult to detect using either voltage or current based test methods. However, it is possible to detect these faults if we add to the conventional dynamic power supply current test methods I_DDT, the analysis of the changes in the slope of this dynamic power supply current. In this work, we present a Built-In Current Sensor (BICS) which is able to process the highest frequency components in the dynamic power supply current of the circuit under test (CUT). The BICS adds to the resistive sensor an inductance made from a gyrator and a capacitor to carry out the current to voltage conversion. Moreover, the proposed test method improves the fault coverage in continuous circuits and switched current circuits as well