A current sensing circuit for IDDQ testing

This paper presents a new built-in current sensor (BICS) that detects defects using the current testing technique in CMOS integrated circuits. This circuit employs cross-coupled PMOS transistor, it is used as a current comparator. The proposed circuit is a negligible impact on the performance of the circuit under test (CUT). In addition, no extra power dissipation and high-speed fault detection are achieved. It can be applicable deep sub-micron process. The validity and effectiveness are verified through the HSPICE simulation on circuits with defects. The entire area of the test chip is 116x65 um(2). The BICS occupies only 41xI7 um(2) of area in the test chip. The area overhead of the BICS versus the entire chip is about 9.2%. The chip was fabricated with Hynix 0.35 um 2-poly 4-metal standard CMOS technology.