A CMOS built-in current sensing circuit

Abstract

This paper presents a current sensing circuit that detects defects in CMOS integrated circuits using the current testing technique. The current sensing circuit is built in a CMOS integrated circuit to test for an abnormal current. The proposed circuit has a very small impact on the performance of the circuit under test (CUT) during the normal mode. In the testing mode, the proposed circuit detects the abnormal current caused by permanent manufacturing defects and determines whether the CUT is defect-free or not. The proposed current sensing circuit is simple and requires no external voltage and current sources. Hence, the circuit has less area and performance degradation, and is more efficient and effective than any previous works. The validity and effectiveness are verified through the HSPICE simulation of circuits with defects.