METHOD OF CALIBRATING A THERMOMETER-CODE SAR A/D CONVERTER AND THERMOMETER-CODE SAR-A/D CONVERTER IMPLEMENTING SAID METHOD

摘要

The present disclosure relates to a method of calibrating a thermometer-code SAR-A/D converter, said thermometer-code SAR-A/D converter comprising a N_bit-bit digital-to-analog converter (DAC) for outputting a N_bit-bit output code, said digital-to-analog converter (DAC) comprising a first subconverter (C_MSB) having a plurality of N_Ththermometer elements T_j (1) and a second subconverter (C_LSB) having a plurality of N_Bin binary-weighted elements (2), wherein said N_bit output code is equal to the sum of N_BitTh and N_BitBin where N_Th = 2^N_BitTh and N_BitBin is equal to N_Bin = N_BitBin. The calibration method includes the steps of determining (5) an Integral Non-Linearity error value (ε_R) of a R^th thermometer-code level of said thermometer elements T_j according to the formula: where E_j represents the relative differences between said plurality of thermometer elements T_j and a reference thermometer element T_ref selected from said plurality of thermometer elements T_j of said digital-to-analog converter (DAC)- minimizing (6) the maximum of said error value ε_R to obtain a minimized error value;- generating (7) said output code (OUTPUT) according to said minimized error.