On-Chip Delay Sensor for Environments with Large Temperature Fluctuations

The precision of on-chip delay sensors is degraded by temperature fluctuations, which hinders these sensors from applying to on-line fault predicting and DVFS. We present a novel path delay measuring technique which is immune to large temperature fluctuation. The delay reference are generated by gate biasing temperature compensation devices in which the pull-up and pull-down network are tuned to set the measurement circuit working in temperature insensitive point, thereby eliminating the precision degradation due to temperature variations. Video image scaling IP is used as experimental circuit to validate the effectiveness of the proposed technique. Experimental results show that within temperature range of -55°C to 125°C, the measurement error is reduced from 19.56% to 0.5%, compared with the techniques without temperature resilience.