Effects of Hot-Carrier Stress on the Performance of the LC-Tank CMOS Oscillators

The effects of hot carrier stress on a fully integrated negative resistance LC-tank CMOS oscillator are investigated. The major effect is the decrease of the amplitude of the oscillation due to degradation in the $I\hbox{--}V$ characteristics of the MOSFETs. The oscillator phase noise increases with stress duration since the amplitude of the oscillation decreases. A change in the biasing of the circuit due to the stress affects the parasitic capacitances in the circuit which in turn cause a slight change in the oscillation frequency.