Abstract: Data acquisition system comprising a circuit for converting a high-frequency analog input signal (a) into a plurality of digital signals (D1-DN, R) for processing by a digital processing system including at least one digital processor (8) comprising a m-bits digitizer (1), a demultiplexer (2) for delivering in parallel N m-bits sample values supplied in series by said digitizer (1), and a memory (5) for storing the demultiplexed sample values, said memory (5) being accessible by said digital processing system (8). According to the invention, the circuit further comprises a real time digital processing circuit (6) for processing in real time said demultiplexed sample values, capable of supplying processed results to said digital processing system (8). The sampling frequency of said digitizer (1) is greater than the input frequency of said digital processor (8).