A bandpass type delta sigma modulation section performs delta sigma modulation on an inputted modulation signal such that quantization noise is reduced in a frequency band which requires low noise. A low pass filter removes a noise component in a high frequency region from the signal on which the delta sigma modulation has been performed. A frequency modulation circuit reduces noise in the frequency band which requires low noise with the bandpass type delta sigma modulation section and the low pass filter, and reduces noise in the vicinity of a direct current component DC with a feedback comparison section and a loop filter.