Silicon Odometer: An On-Chip Reliability Monitor for Measuring Frequency Degradation of Digital Circuits

A fully-digital reliability monitor is presented for high resolution frequency degradation measurements of digital circuits. The proposed scheme measures the beat frequency of two ring oscillators, one which is stressed and the other which is unstressed, to achieve 50X higher delay sensing resolution compared to prior techniques. A reliability monitor test chip has been fabricated in a 1.2 V, 130 nm CMOS technology.