Method and apparatus for accumulation of electric charge delivered to the charge input (InQ) in the sampling capacitor (Cn) and in realization of the process of charge redistribution in the array of redistribution (A) by changing states of signals from relevant control outputs and in assignment of relevant values to bits in the digital word by means of the control module (CM). Method is characterized in that after detection of the beginning of the next gate signal (Gx+1), the charge is accumulated in the additional sampling capacitor (CnA), and then the process of charge redistribution is realized and relevant values are assigned to bits of the digital word. When the beginning of the subsequent gate signal (Gx+2) is detected, the next cycle begins and electric charge is accumulated in the sampling capacitor (Cn) again.