I/sub DDQ/ testing is a powerful strategy for detecting defects that do not alter the logic behavior of CMOS ICs. Such a technique is very effective especially in the detection of bridging defects although some opens can be also detected. However, an important set of open and parametric defects escape quiescent power supply current testing because they prevent current elevation. Extending the consumption current testing time, from the static period to the dynamic one (i.e. considering the transient current), defects not covered with I/sub DDQ/ can be detected. Simulations using an on-chip sensor show that this technique can reach a high coverage for defects preventing current and also for those raising the static power consumption.