| 摘要 |
PROBLEM TO BE SOLVED: To provide an analog-digital converter capable of performing appropriate operation even when the center frequency of an analog input signal is high.SOLUTION: An analog-digital converter 4 comprises: a sample and hold circuit 6 to which an analog input signal is input; and a band pass ΔΣ modulator 7 that performs ΔΣ modulation on an output signal output by the sample and hold circuit 6 to output the modulated signal as a digital signal. A sampling frequency fof the sample and hold circuit 6 is set to be lower than the center frequency fof the analog input signal.SELECTED DRAWING: Figure 2 |
