Built-in-self-testing techniques for programmable capacitor arrays

Programmable capacitor arrays (PCA) are frequently used in reconfigurable analog circuits. Since PCA can be programmed to numerous values, testing PCA by exhaustively examining all PCA values can lead to lengthy testing processes. To address this problem, we present an efficient built-in-self-testing (BIST) method for PCA used in reconfigurable analog circuits. The proposed BIST method takes advantage of existing programmable resources and, hence, introduces very small hardware overhead. Additionally, we present two simple and effective capacitor comparison techniques for implementing the proposed BIST method. The accuracy of the proposed circuit techniques is investigated and closed-form equations are derived for estimating comparison accuracy that can be achieved by the proposed techniques. Finally, circuit simulations are performed to validate the proposed techniques.