An analog checker with input-relative tolerance for duplicate signals

We discuss the design of a novel analog checker that monitors two duplicate signals and provides a digital error indication when their absolute difference is unacceptably large. The key feature of the proposed checker is that it establishes a test criterion that is dynamically adapted to the magnitude of its input signals. We demonstrate that, when this checker is utilized in concurrent error detection, the probability of both false negatives and false positives is diminished. In contrast, checkers implementing a static test criterion may only be tuned to achieve efficiently one of the aforementioned objectives. Likewise, when the proposed checker is employed for off-line test purposes, it results simultaneously in both high yield and high fault coverage.