| 摘要 |
PURPOSE:To magnify the dynamic range of a signal to be handled, by constituting an A/D converter circuit of a multiplier making the dynamic range of an analogue echo signal variable, an A/D converter and a data converter for converting the output data of the A/D converter. CONSTITUTION:The analogue signal from a delay circuit 13 of an analogue system is inputted to the first A/D converter 23a as it is and inputted to the second converter 23b while the dynamic range of the signal is made variable by a multiplier 22. When k=5 is set in the multiplier 22 and the magnification thereof is set to 1/2<5> while m=10 is set in the first and second A/D converters 23a, 23b and the number of bits thereof are set to 10bits, two 10-bit A/D converters (23a, 23b) are used from the relation between the input and output data from the first and second A/D converters 23a, 23b to a data converter 24 to realize an A/D converter circuit 14 having a 15-bit dynamic range as a whole. |
