Audio Amplifier (TDA7297) getting too hot..

[ihansw]

MP3(GPD2856C)+AMP(TDA7297)+Speaker(10W 4Ohms) Module

Hello guys,

I am a newbie to this, and trying to build a simple mp3 player module using GPC2856C(mp3 decoder), TDA7297(audio amp), and 10W 4Ohms speaker. As you can see in the pictures, I simply purchased two modules and put them together.


1. I took out the built-in amp from the MP3 decoder board, and connected the audio signals (+ and -) into the input and ground of the AMP board.

2. Connected the speaker to the AMP board.

Result: Everything works fine. I can hear a clear and loud sound of music that is read from the SD card thanks to TDA7297.

Problem: TDA7297 chip gets really hot. I can probably keep it going for a few minutes with the power control knob in the middle state (there is a knob I can spin to control how much power will be used which results in volume change). But it gets so hot that after a minute that I can't touch the heatsink with my fingers. I know that amp usually gets warm in performance, but I am not sure it's supposed to get this hot. Please give comments if I did anything wrong here!

Thanks,

* the pdf is not exactly the right one but it's very close to the mp3 board (GPD2856C) and I was able to sort of understand how the board works

 

[ihansw]

Hi guys,

I need some help on using my audio amplifier module, TDA7297. It's working fine but it gets really hot while it's operating. Basically, I can't touch the heatsink after a few minutes because it's too hot. I took measurement of the current and it went from 200mA up to 1A, sometimes. I am not sure if it's supposed to go this high. I am afraid I might burn the chip. Is it supposed to get this hot? Am I doing something wrong? Do I need a bigger heatsink?

GPD2856C MP3 Decoder and Play Board, w/Amplifier - ElectroDragon

Above link shows the module I am using.

Please give me any advice or ideas! Thanks.

 

[Mooly]

Does it get hot with no music playing ? The current consumption of this chip is fairly low, around 65ma quiescent. That means it should run cool under those conditions. Supply voltage no higher than 18 volts.

 

[farley]

What circuit are you using for the TDA7297 amplifier?
What power supply are you using for the TDA7297 amplifier?
How are you feeding the audio signal from the MP3 module to the TDA7297 amplifier?
Can you show a picture of the complete system?

 

[Mooly]

I've merged your two threads into one. Please don't start multiple threads for the same topic.

 

[ihansw]

Thank you for leaving comments. And I apologize for posting two threads for the same topic Mooly.

The amp does NOT get hot with no music. Only when I turn on the music and raise the volume up, the amp starts to get hot. (with high current reading).

I am putting about 17V for the amp.

I am basically reading music files off a SDcard and connecting the audio signals to the inputs of the amp module.

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Above are pictures of the full system.

Thank you for your help!

 

[Mooly]

Having seen the size of the heatsink... it 'aint big enough. Not by a long way.

 

[ihansw]

So if I use a bigger heatsink, current value of 200mA - 1A is not a problem?

 

[Mooly]

Yes, it needs to be a lot bigger. Something around 50% of the size of this at a guess,

https://cpc.farnell.com/velleman-ki...ChJVQPZ7HkUZ YXxE+9fmrKE7AZGogFnoohi7+LAAd3w=

 

[nigelwright7557]

Having seen the size of the heatsink... it 'aint big enough. Not by a long way.

That was my thoughts too.
Way too small.
You need to work out how many watts the chip amp is dissipating then find the correct heat sink that keeps temp below about 60 degrees C under full power.

 

[ihansw]

Oh wow, it really needs to get a lot bigger. Okay, thank you so much for your diagnosis.
I was concerned about the strangely high current measurement, but I guess that's normal!

I really appreciate your help. 🙂

 

[ihansw]

That was my thoughts too.
Way too small.
You need to work out how many watts the chip amp is dissipating then find the correct heat sink that keeps temp below about 60 degrees C under full power.

Thank you! I will keep this in mind.

 

[farley]

So if I use a bigger heatsink, current value of 200mA - 1A is not a problem?

In addition to a larger heatsink you might also try a larger 6 to 8 ohm speaker in a proper enclosure. I'm thinking you're having to drive the amp pretty hard to hear your music from the little speaker laying on the desk.

 

[nigelwright7557]

18 volts and 1 amp gives 18 watts.
To stay below 60 degree c means a 2 degrees C / watt heat sink.
If my maths is right.

 

[ihansw]

It really is the heatsink after all. I didn't realize how important that piece of metal was for amplifiers.

I really appreciate your help guys. Thanks!

 

[Mooly]

You're very welcome 🙂

 

[limpidaudio]

I use these modules all the time, NEVER power them over 12V, they are meant for car use.
The more recent ones come with larger heatsinks and still get warm.
Also, 8 ohm speaker is the minimum I would use and ensure you arent grounding the speaker to the power anywhere as these are bridge amps and that will make them overheat also.

Hope this helps!

 

[radiosmuck]

For the last 3 years I have had a tda7297 connected to a large pair of 15 inch Tannoy speakers and the small heatsink never goes much above ambient.
If you have inefficient speakers then you should perhaps invest in a different board.

 

[Destroyer OS]

Heatsink is way small. Twist your power wires, and output wires.

The output is balanced.