| 摘要 |
PROBLEM TO BE SOLVED: To provide an FM wave demodulation circuit capable of obtaining the same data from the demodulated signal voltage of an FM wave demodulation circuit using a digital delay circuit with satisfactory reproducibility even when the fluctuation of components or the change of a temperature is observed. SOLUTION: In this FM wave demodulating circuit, an FM wave is received, and its frequency is converted into an intermediate frequency, and converted into a logic level by a level converting circuit, and the output signal of the level converting circuit is branched, and one output signal is directly inputted to one input terminal of an excusive logical sum circuit, and the other output signal is transmitted through a gate delay circuit so as to be delayed byΔt, and inputted to the other input terminal of the exclusive logical sum circuit, and the pulse column of the exclusive logical sum signal is outputted, and applied to a low pass filter and averaged so that a demodulated signal can be outputted (1). This demodulation circuit is provided with an analog switch arranged in the pre-stage of a level converting circuit for switching an FM wave intermediate frequency signal and a signal for correction (2), and a signal for correction generating source for generating a signal for correction (3), and a D/A converter for varying the power supply voltage of a gate delay circuit capable of changing the power supply voltage (4).
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