I'm currently working on a simple audio amplifier circuit using the TDA7052 IC.
So far I have been able to achieve amplification, with a little distortion.
My problem is that I'm observing a large DC offset at the audio output, and the IC is getting very hot.
I'm feeding in 12Vdc and the amp is drawing around 100mA, which makes for 1.2W of power. The gain is set to 20dB with pin #4 being driven at 1Vdc.
Here is my circuit:
And here are the input and output waveforms (Yellow waveform taken at pin 8, with reference to system ground):
So, the input is being driven with a signal generator with the parameters displayed. The output is indeed being amplified, but it has a DC average value of around 5V, how do I remove this DC offset? and is there a way to mitigate this slight distortion?
I've tried adding two 10uF caps in series with OUT+ and OUT-, this is what happened: (and I'm not surprised, the datasheet doesn't show them in the typical application circuit, nor do other implementations found on the internet).
Best Answer
What you have is a bridge output which is self biased to be at 1/2 the supply voltage. That is normal. The outputs will be at or close to 1/2 the power supply voltage with no signal.
If the IC is getting hot, well it needs to be mounted to a heat sink. Aluminum is fine. 1.2 watts is very hot to touch, so a heat sink is mandatory.
It sounds like you have a perfectly good amplifier that is just missing a heat sink. All of your parameters (100 mA for bias current for bridge output) seem normal and you stated it put out a clean sound, so I do not think anything is wrong-except for a missing heat sink.