A continuously-calibrated 10 M sample/s 12 b 3.3 V ADC

Continuous calibration allows a converter to function continuously in the presence of environmental fluctuations and supply variations by periodically correcting for errors without interrupting the ADC output. This paper introduces a technique for continuously calibrating a pipelined A/D converter. Calibration is performed in the analog domain so as to avoid high-linearity calibration hardware or complex signal processing. A 10 MS ample/s, 12b converter implemented in a conventional 0.5 /spl mu/m, single-poly, four-metal, CMOS technology operates from a 3.3V supply. This experimental circuit digitizes a 4.8 MHz signal with a peak SNDR of 67 dB.