In the design of management information and control systems, a good deal of attention is devoted to what are called peripherals – facilities external to central processor (or computer), whose purpose is to gather, reduce and convey data from source to sink. In this paper is described an feedback analog-to-digital converter build whit DAC08 digital-to-analog converter. The structure of the analog-to-digital converter are presented and mode of operation are analyzed. The experimental results are presented and the time performances are considered.