Design and realization of an accurate built-in current sensor for on-line power dissipation measurement and I/sub DDQ/ testing

Abstract

Built-in current sensor (BICS) is known to enhance test accuracy, defect coverage and test rate of quiescent current (I/sub DDQ/) testing method in CMOS VLSI circuits. For new deep-submicron technologies, BICSs become essential for accurate and practical I/sub DDQ/ testing. This paper presents a new BICS suitable for on-line power dissipation measurement and I/sub DDQ/ testing. Although the BICS presented in this paper is dedicated to submicron technologies that require reduced supply voltage, it can also be used for applications and technologies requiring normal supply voltage. The proposed BICS has been extended for on-line measurement of the power dissipation using only an additional capacitor. Power dissipation measurement is important for safety-critical applications and battery-powered systems. A simple self-test approach to verify the functionality and accuracy of BICSs has also been introduced. The proposed BICS has been implemented and tested using an N-well CMOS 1.2 /spl mu/m technology. Practical results demonstrate that a very good measurement accuracy can be achieved.