Difference between the TDA2009 and the TDA2009A?

Discussion in 'General Electronics Chat' started by cumesoftware, Feb 2, 2010.

  1. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
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    Today I was testing the output stage of my Minimus amplifier on a breadboard. I was testing with a TDA2009 from SGS Thompson, a bit different from the TDA2009A from ST that I will be using on my final project. Using 4Ohm speakers and under 19V regulated supply current, the sound was perfect and the bass was clean without distortion at near maximum levels. No perceptible noise with 0V RMS input, except perhaps a bit of humming due to a ground loop (the input came from my computer) and the gain was perfect.

    It went wrong when I decided to test it for shorts. I shorted the output to the right speaker (from the negative of the output capacitor, a 2200uF electrolytic, to ground). The sound to the left speaker could be heard normally, pretty loud (input was maximum then) for about 15 seconds, but then it came mute. I assumed it was the thermal protection, so I shut down the power and let it cool (it was hot, even with an heatsink and 15ºC ambient temperature). After a while I turned the amplifier on with the short removed, and it was mute. After a while, the IC smoked by itself without any input, same circuit as before, and blew. Fortunately, the breadboard went undamaged.

    So, should I assume that the TDA2009 (not the "A" version) doesn't have short circuit protection, while the TDA2009A does? Or that the chip I held was counterfeit? I can only find the datasheet for the TDA2009A from ST. There is no datasheet for the non "A" version.
     
    Last edited: Feb 2, 2010
  2. Audioguru

    New Member

    Dec 20, 2007
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    I also couldn't find the datasheet of the TDA2009 from SGS Thompson, but found the one by Unisonic in Taiwan. Theirs has Short Circuit and Thermal Protection.
     
  3. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
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    I found that datasheet too, but I wouldn't rely on it. It seems that I have to buy another TDA2009A from ST. I just hope the store has one. Then I will test it for shorts.

    On the other hand, the TDA2003 from ST handles shorts pretty well and has excellent thermal protection.
     
  4. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
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    I did the same test today with a spare TDA2009A, and I concluded that it has short circuit protection, and a pretty good one. I seems that the TDA2009 doesn't have that feature.

    I will test another TDA2009 again, but now using an old chip from ST (a vintage chip before the "A" version that is being sold in some places).
     
  5. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
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    The TDA2009 from ST seems to have short circuit protection too. But I still think the TDA2009A performed better. I think that concludes the testing, and the chip that blew might be a counterfeit.
     
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