| 摘要 |
PURPOSE:To increase the number of effective bits, by performing the analog- to-digital-coversion of an input signal in a different rate, and outputting selectively data in response to the overflow state. CONSTITUTION:An alalog signal is shrunk or enlarged at rating converters 21, 22. The rate of conversion depends on each converter. The output of the convertes 21, 22 is digital-coded at A/D converters 31, 32. The converting ratio of the converter 22 is determined so that the output signal of the A/D converter 32 overflows earlier. While the analog signal is smaller and the converter 32 does not overflow, a gate 51 is closed and a gate 52 is opened. Thus, the output of the converter 32 is given to a processor 60. When the converter 32 overflows, the gate 51 is opened and the gate 52 is closed. Thus, the output of the converter 31 is given to the processor 60. |
