Inverting power amplifier circuit composed of LM4732

As shown in the figure, this is an inverting power amplifier circuit composed of LM4732. After the audio signal is input, it is coupled to the inverting input terminal of the amplifier through CIN and Ri, while the non-inverting input terminal of the amplifier is grounded, thus forming an inverting power amplifier circuit. Switch S1 is used to set the squelch mode. When S1 is disconnected, it is in squelch mode and the audio signal is prohibited; when S1 is closed (connected to -VEE), it is in normal working mode and the audio signal is amplified normally. The characteristics of the inverting power amplifier circuit are: it has good total harmonic distortion and noise characteristics (THD N); the output coupling capacitor can be eliminated to save circuit cost and space; the gain Av = -Rf/Ri, and the gain of this circuit is 20.