Surround sound circuit consisting of TDA3810

Photocoupler

This article is shared today by a surround sound circuit consisting of a dedicated high-fidelity surround sound processing integrated circuit TDA3810. As shown in the figure below, the stereo signal is input to the input coupling capacitors cJ and C2, and the pins 2 and 17 are buffered by the internal amplifier. The left and right channel signals are divided into two paths. One way is directly output from the 3rd and 16th feet, which is used as the signal of the main speaker, and the other is sent to the active phase shifter for phase shifting. At the same time, the active phase shifters of the left and right channels realize the inverse between the two channels through the common resistor R. The phase crosstalk forms a (L-foot) and (R-L) signal. The crosstalk depth depends on the ratio of R4 (Rs) to Rg. The larger the Rg, the shallower the crosstalk depth. The outer brain element R3, C4, q (Rs, R7 Cii, C12) and an internal operational amplifier and resistor constitute an active phase shifter. The degree of phase shift can be adjusted by changing the resistance of R(R5). The larger the resistance, the larger the phase shift. After the reverse phase crosstalk and the phase-shifted towel (L-R) and the R-L signal, the signal is output from the 613 pin as the signal of the left and right sub-speakers through the electronic selection switch inside the circuit. .
An electronic selector switch is used to select the operating state of the circuit. When the switch SA on pin 11 is turned off, pin 1 is high and the circuit is in surround sound. When the switch SA is closed, the 11th pin is placed at the 0 level, and the circuit is in the stereo operating state, that is, the through state. At this time, the stereo signal is input from 2, 17 feet, and is directly output from the 3, 16 and 6, 13 pins via the electronic selection switch. The LED VDi on the 7-pin is used to display the surround sound working state.