New HCI and TDDB sensors based on transition time monitoring

A new on-chip hci sensor based on measurement of fall transition time difference due to hci between a stressed and reference inverter is proposed that has very small resolution while output has high correlation with hci effect. based on this new idea, a novel tddb sensor is also proposed that is capable to detect both soft and hard breakdowns while it has low area overhead and high sensitivity. differential structure of both sensors eliminates the effect of common-mode environmental variation, such as temperature. 180 nm tsmc technology and 65 nm of ptm are used for simulation. analysis confirms hci and tddb sensor performances with 17% and 15% errors, respectively, in comparison with simulation results. the implemented layout area of both sensors is 101 × 18 µm^2.