| 摘要 |
PURPOSE:To obtain a pulse width modulating signal with simple constitution and less distortion by constituting so that an output pulse wave is integrated to apply negative feedback to an input signal and a part supplying a modulating carrier signal is formed in a negative feedback loop. CONSTITUTION:An input terminal 1 is connected to a non-inverting input terminal of an operational amplifier 10 and a capacitor C1 is connected between an output of the operational amplifier 10 and an inverting input terminal. The output of the operational amplifier 10 is led to a non-inverting input terminal of a comparator 5. On the other hand, an output of a rectangular wave oscillator 3 is connected to an inverting input terminal of the comparator 5 through an LPF11. The output of the comparator 5 is led to an output terminal 8 and also one end of a resistor R1 is connected to the output. The other end of this resistor R1 is grounded through a resistor R2 and a resistor R3 is connected between a connecting point of the resistors R1, R2 and the inverting input terminal of the operational amplifier 10. Through the constitution above, the pulse width modulation amplifier circuit with less distortion is obtained. |
