| 摘要 |
PURPOSE:To reduce the distortion of the output low-frequency signal, by selecting the reference voltage of the 1st and 2nd comparators each in order to secure the minimum distortion factor for the output low-frequency signal supplied from the low pass filter. CONSTITUTION:The input signal sent from input terminal 1 is applied to integrator 10, and then the triangular wave signal of the carrier frequency sent from rectangular wave oscillator 12 is applied to integrator 10. Then the rectangular wave signal is piled onto the input signal, and this piled signal is applied to the 1st and 2nd comparators 13-1 and 13-2 which compare the reference voltage of different reference voltage generation sources each. Thus driving circuits 15-1 and 15-2 are operated by the outputs of comparators 13-1 and 13-2, and the alternating control is given to the ON/OFF of transistors Q1 and Q2 via impedance converting circuits 16-1 and 16-2. Then the reference voltage of these two comparators are selected so as to secure the minimum distortion factor for the low-frequency signal of the circuit which is connected to output terminal 2 of LPF4 to obtain the low-frequency output. Thus the minimum distortion is secured for the output low-frequency signal. |
