| 摘要 |
PROBLEM TO BE SOLVED: To reduce the asymmetry of an amplitude by a smaller circuit scale. SOLUTION: An ADC 313 includes a front end adjusting part 60 indicated by a broken line, and a discretization part 62. When the amplitude of an analog signal inputted from an input part is present in a nonlinear section, the ADC 313 converts the analog signal into a digital signal to output it while adjusting the amplitude of the analog signal. In other words, the front end adjusting part 60 adjusts the amplitude of the analog signal to cancel nonlinearity in the nonlinear section before the analog digital conversion part converts the analog signal into a digital signal. Specifically, the front end adjusting part 60 adjusts the amplitude of the analog signal in the nonlinear section by setting input/output characteristics in the nonlinear section to a value approximate to the inverse number of a hyperbolic tangent function. Then, the discretization part 62 converts the analog signal whose amplitude is adjusted by the front end adjusting part 60 into a digital signal and outputs the resultant signal. COPYRIGHT: (C)2007,JPO&INPIT
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