Quiescent current sensor circuits in digital VLSI CMOS testing

Many integrated circuit processing defects may cause changes in the value of the quiescent power supply current. Not all of these changes are detectable using classical functional testing techniques. Testing techniques based on the quiescent power supply current inspection have been reported to be efficient in the detection of a wide set of well known physical defects (including bridges and stuck-on). Two quiescent current sensor circuits are proposed and discussed. These circuits are oriented to different testing applications such as the external functional ATE environment, and the built-in self-testing (BIST) design for both on-line and off-line strategies.