A calibration technique for mismatch of capacitor arrays in A/D and D/A converters

This paper proposes a new calibration technique for capacitor array SAR (Successive Approximation Register) ADC, here we focus on the true value and the true weight of each capacitor. By measuring the capacitor, we calculate the true weight (W_i) of each weighted-capacitor, and map this weight into m-bit code C_i(m≥n). With the normal conversion code D_i(n-bit), we define the first n-bit of Σ_Di*Ci as the ultimate output code. The simulation indicates that this method can greatly suppress harmonics, and the ENOB gets improved greatly.