High-precision Sigma-Delta Modulator with improved linearity

In this thesis, the development and implementation of a high-precision Sigma-Delta modulator is described. The objective of this thesis was to investigate the possibility of merging a current mode feedback instrumentation amplifier with the following analog-to-digital converter into one sigma-delta modulator. For this purpose, a continuous-time sigma-delta modulator with input transconductor is chosen which can limit the linearity performance of the system. A new method is proposed which has improved the AC linearity by almost 40dB. The system is implemented in a 0.7 µm CMOS process and with this technique, the linearity is comparable with the state-of-the-art designs.