Filter characteristic regulating apparatus and regulating method therefor

Abstract

A filter characteristic regulating apparatus for regulating a characteristic frequency of a filter device capable of regulating a characteristic frequency includes a measuring signal generator for generating a measuring signal having a known cycle of a response waveform when inputted to a filter device having a desired characteristic frequency, a selector for selecting and inputting this measuring signal to the filter device when the filter device is not used, a response waveform cycle measuring instrument for measuring the cycle of the response waveform of the input measuring signal to the filter device, and a controller for comparing the cycle of the response waveform measured by the response waveform cycle measuring instrument with a known response waveform cycle, and regulating the characteristic frequency of the filter device to a desired value on the basis of the comparison result. Because the measuring signal having a known cycle of the response waveform when inputted to the filter device is used in this way, the filter characteristic can be regulated without executing a complicated operation at the time of regulation. Therefore, this filter characteristic regulating apparatus can be assembled with the filter device in one semiconductor device.

Dependencies are inferred from the claim text.