AD CONVERSION APPARATUS AND METHOD

摘要

It is realized to provide digital signals whose levels have been appropriately controlled for the respective samples. An input signal is supplied to amplifiers whose gains are one, two, four and eight times. Outputs from the amplifiers are simultaneously converted to digital signals by respective AD converters having the same characteristics. The digital signals are inputted to a data selecting part, in which, when an input signal is large, the AD converter, associated with the signal having passed through the amplifier whose gain is large, overflows and exhibits an over-bit of "1". The output digital signal of the AD converter connected to the amplifier whose gain is the largest of the amplifiers connected to the AD converters exhibiting over-bits of "0" is selected and outputted. Then, this digital signal is scale-corrected and outputted.