Built-in fault testing of integrated circuits

摘要

Built-in current mode quiescent current monitoring circuitry is provided for measuring a circuit's or a subcircuit's quiescent current. Anomalously high quiescent current (Iddq) generally results as a consequence of a manufacturing defect. These defects include those not detected by tests generated using traditional fault models. The technique provided here is based upon generating a proportionally matched current to the circuit under test current by a control loop. The proportionally matched current is then sent to a comparator where it is compared to a reference current, the reference current representing an acceptable quiescent current level. The output of the comparator then indicates whether the quiescent current is above or below the reference current.