TDA7396 Troubleshooting

[juam_r]

I want to configure this Amplifier as single-ended mode operation. I currently have this configuration, but does not seems to work correctly: output signal is very noisy, input current is very high, sometimes the TDA does not power on and needs to be reset to turn it on. Could anyone explain how to properly configure the TDA for such operation mode and explain the reasons behind that. Thanks
*Diagram explanation: only input 2 of TDA is being used, pin 8 is externally controlled and goes to +8V, Tx is the output signal and supply voltage is 8V which could be increased to make the amplifier work properly if needed (i.e. 8.2V to turn on the TDA but still the issue remains). The diagram corresponds to TDA7396.

 

[unclejed613]

the (+) side of all electrolytic capacitors should be connected to the chip, not to ground. backward electrolytic caps will leak a lot of current.

use a larger cap (470uF or higher) to couple the speaker to pin 7. here is the [data sheet] . you are trying to run this amplifier with only half of it driven, and running the chip at it's absolute minimum VCC. you are not going to get much power out of the chip amp (about 3.5 watts)

 

[audioguru]

The TDA7396 is made for low impedance speaker that is 2 ohms or 4 ohms. Its output is bridged for 15W into a 4 ohm car speaker or 30W into a 2 ohm speaker when the battery is 14.4V. You are using a low supply voltage and only one of its outputs. Then its output power into an 8 ohm speaker is only about 0.6W, slightly more than a little LM386 amplifier.

Pin 5 is one of the outputs of this amplifier. But you use C31 (10uF) to short high audio frequencies to ground. The short circuit current makes lots of heat.
Your output coupling capacitor is 22uF plus 10uF= 34uF. Then it passes frequencies above 588Hz to an 8 ohm speaker. No bass.