The study of parameter drift due to interface defect generation in “Off” mode or near Vth is very complex, because it is often concomitant with hot hole trapping which induces turnaround effects. Improving device aging models requires to consider hot-carrier degradation (HCD) in “On/Off states”, interaction of these different modes as well as any dynamic effects. The DC characterization of HCD modes might be insufficient, it is necessary to verify the quasi-static assumption made when we seek to model the degradation under realistic dynamic stress by a secession of static states. We present a detailed analysis of the interactions of HCD under “On” state and “Off” state”. Pulsed stressing are used to analyze the frequency dependence of HCD and “Off-state”. Such approach is required for accurate AC RF ageing modeling.