ANALOG/DIGITAL CONVERTING CIRCUIT

摘要

PURPOSE:To facilitate the conversion level setting and the offset adjustment exactly at each channel by providing an excess input detection circuit and outputting an overflow signal directly from the A/D converter. CONSTITUTION:The overflow detection circuit 38 outputs the information of the (M+1)th bit of a limiter 36 as a clip indicator signal and outputs the information of the (M+2)th bit to discriminate whether overflow or underflow takes palce, and lights an overflow indicator 40 or an underflow indicator 41 via a drive circuit 39. Then an input level adjusting circuit 3 and an input offset adjusting circuit 5 provided to the input side of the A/D converter 1 are controlled and the input level is matched to a level at which both the overflow and underflow indications are extinguished. Thus, both the offset and the input level are set easily.