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  What is Temp Inversion? As the temperature increases, the delay of the cell can Decrease due to decrease in threshold voltage (Vt). Increase due to decrease in the mobility. Delay of a cell may decrease or increase depending on the dominant effect of mobility and threshold voltage (Vt), that is what defines the resulting thermal trend related to temperature inversion effects. If Gate overdrive voltage (Vdd - Vt) is large then the decrease in threshold voltage due to temperature variation is negligible. But the mobility effect dominates, with the result that the delay of the gate increases with temperature increases. But, if Gate overdrive voltage (Vdd - Vt) has reduced such that the decrease in threshold voltage effect dominates and delay decreases with the increases in temperature. So, at 65nm and below, the threshold voltage (Vt) has not been reduced much but the supply voltages has reduced considerably to cater low leakage power concerns. The result is that the gate overdrive volt