Reducing Impact of Degradation on Analog Circuits by Chopper Stabilization and Autozeroing

Shailesh More1,  Michael Fulde2,  Florian Chouard1,  Doris Schmitt-Landsiedel1
1Institute for Technical Electronics, Technical University of Munich, Germany, 2Infineon Technologies AG, Villach, Austria


This paper shows that chopper stabilization and autozeroing, commonly used to eliminate offset and low frequency noise, can also significantly reduce the effects of transistor degradation caused by hot carrier and BTI stress in analog circuits. An open loop amplifier circuit designed in a 32nm high-k, metal gate technology is investigated by circuit simulation and sensitivity analysis. This analysis was conducted using DC stress which can cause high offset for asymmetric input signals. Aging due to negative and positive bias temperature instability, conducting and non-conducting hot carrier injection is taken into consideration. The aging contributions of these effects on the individual transistors in the circuit and on the amplifier offset are evaluated and a drastic reduction of the output offset is obtained by chopping and autozeroing.