| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce spurious components depending on the periodicity of an output signal without increasing a noise floor and while ensuring stability of a sigma-delta modulator.SOLUTION: A sigma-delta modulator S breaks the periodicity of an output signal Y while maintaining a constant time average of the output signal Y, to reduce spurious components depending on the periodicity of the output signal Y. The sigma-delta modulator S includes: a sigma-delta modulation section 1 having an integration circuit for integrating an input signal X to generate an integral signal, and a quantization circuit for quantizing the integral signal to generate the output signal Y; and an integral signal value updating section 2 for, in repeatedly updating a signal value of the integral signal, making a measured value of a time average of the output signal Y between timings of updating the signal value of the integral value, equal to a ratio of a DC component of the input signal X to a quantization step width of the quantization circuit.</p> |
