HOT CARRIER STRESS EFFECT ON THE PERFORMANCE OF SECOND ORDER OVERSAMPLING CMOS DELTA-SIGMA MODULATOR
Rajiv Soundararajan, Ashok Srivastava · 2010 GSW Proceedings · 2022
This work investigates the effects of hot carrier stress on the characteristic and performance of a second order oversampling delta-sigma modulator of an analog-to-digital converter as a function of stress time and temperature.The stress time is varied up to 4 hours and temperature up to 150 o C. The modulator is designed in 0.5µm CMOS n-well process with hot carrier effect (HCE) modes.The performance degradation of a CMOS amplifier under HCE is also investigated in detail which is used in modulator design.SPICE is used for the post-layout simulations and HCE is observed through the MOSFET threshold voltage variation in the MOS modeling.The gain of the amplifier which is dependent on the transconductance and drain conductance of the differential pair changes during hot carrier stress.This causes noticeable degradation in the resolution of the modulator.