LM4820-6 audio power amplifier circuit

As shown in the figure, this is the audio power amplifier circuit of LM4820-6. After the audio signal is input, it is added to the INPUT1 terminal (pin 3) of the amplifier after Ci coupling, while the INPUT2 terminal (pin 4) of the amplifier is not connected, and the amplified signal is output from pins 5 and 8. A load such as a speaker is connected between pins 5 and 8 to form a power amplifier circuit. There are two amplifiers inside LM4820-6, and there are two 25kΩ resistors inside to set the closed-loop gain. The circuit gain of Amp A1 and Amp A2 is 1; the differential output gain Av=2Rf/Ri.