A circuit for selectively converting at least one analog signal into corresponding digital codes. The circuit includes a management block having a plurality of inputs, each adapted for receiving a respective request signal carrying a request to convert the at least one analog signal. The management block is adapted to assign a priority level to the request signals based upon the input where the request signals are received, and is further operative to select one of the request signals based upon the assigned priority level and output a conversion start-up signal corresponding to the selected request signal. The circuit has a conversion block for receiving east one analog signal input and is connected to the management block to receive the conversion start-up signal as input, and start up conversion of the at least one analog signal.