Fully integrated BTL power amplifier circuit

LM1875 is a monolithic integrated amplifier circuit produced by National Semiconductor Company. It has
the characteristics of high output power, low distortion, wide frequency response, and large dynamic range. The circuit is equipped with safety protection circuits such as overload, overheating and reverse electromotive force suppression.
It is an excellent single-chip power amplifier circuit and is widely used. Figure 2-49 is a
BTL power amplifier circuit composed of LM1875 and TA7630 .
    The input and volume and tone control of the circuit adopt Toshiba's integrated tone and balance control integrated circuit
TA7630. This integrated circuit is a dual-channel DC volume, tone and balance control circuit. It has a wide power supply voltage range
(single power supply 8~14V, dual power supply Power supply ±4V ~ ±7V), large volume control range (80dB), tone control up to 15dB,
small temperature drift, small cross-talk, and stable operation.
    The power amplifier adopts BTL connection method. The output power can reach 80W, distortion ≤1%, quiescent current <200mA, maximum
output current up to 8A, conversion rate is 8V/yso.
    The signal is input from cl to pin 15 of T'A7630, and passes through After volume and tone processing, they are input to input terminal 1 of
LM1875 through C14 and RJZ. R13.R16 are negative feedback resistors, used to adjust circuit gain and improve distortion. C19,
‰ and Ri8.R20 are decoupling networks used to eliminate high-frequency self-excitation. C16 and C[7 are power supply filter capacitors.
    VTi and other components form an electronic power filter circuit to provide stable and pure DC power supply for TA7630. RPi integrated) 4
buttons are control potentiometers for balance, volume, bass and treble o -