Deterministic Dither Based Mismatch Characterization of Wide Range of Metal-Oxide-Metal Capacitors

This paper proposes a deterministic dither based capacitor mismatch measurement using a low-resolution analog-to- digital converter for a wide range of Metal-Oxide-Metal capacitor values (20 fF to 1 pF), thereby facilitating easier integration alongside actual blocks which use those capacitors. In this work, deterministic dithering has been demonstrated to be an effective method for mismatch estimation, reducing hardware overhead and relaxing the design of the analog-to-digital converter used to obtain the mismatch. System level simulations using MATLAB and subsequent circuit level simulations in UMC 65-nm show that the proposed technique can measure absolute capacitor mismatch to within 15-bits of accuracy and also statistically characterize capacitor mismatch having standard deviation as small as 0.01 %.