Published in Laknaur, A., Xiao, R., Durbha, S., & Wang, H. (2007). Design of a window comparator with adaptive error threshold for online testing applications. Proceedings of the 8th International Symposium on Quality Electronic Design (ISQED'07), 501-506. doi: 10.1109/ISQED.2007.57 ©2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.


This paper presents a novel window comparator circuit whose error threshold can be adaptively adjusted according to its input signal levels. It is ideal for analog online testing applications. Advantages of adaptive comparator error thresholds over constant or relative error thresholds in analog testing applications are discussed. Analytical equations for guiding the design of proposed comparator circuitry are derived. The proposed comparator circuit has been designed and fabricated using a CMOS 0.18mu technology. Measurement results of the fabricated chip are presented.