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  1. #1
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    TDA7294 with power BJT...... blown ic chip ....

    I am working on a TDA7294 outputted with a 2SC5200 and 2SA1943 pair....The design seems to be very popular and I got it from a website called 320volt.com. After making the PCB successfully, I tested it on a PC SMPS but mistakingly connected 0 volt and negative and this led to a lot of heating mainly in IC and too some extent in the BJTs. Afterwards, I connected it properly and everything went smooth....I was able to hear the sound... No problem with heatsinks...

    Yesterday, I made a dual rail supply of 30-0-30 volt and connected it to the amp. I used filters and all..made the connections proper....but the IC blew up.....

    What could be the reason ?????

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  2. #2
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    Re: TDA7294 with power BJT...... blown ic chip ....

    Just guessing: High frequency oscillation and no (fold-back) current limiting in your dual rail supply?



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  3. #3
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    Re: TDA7294 with power BJT...... blown ic chip ....

    The datasheet for the TDA7294 does not show it with booster transistors. The datasheet of the TDA2030A shows it with them.
    I found three TDA7294 amplifiers from 320volt.com. One was blocked by my anti-virus software as being unsafe (with a virus?), one has the ordinary 100 Whats (70 Watts) circuit and one has the circuit with two TDA7294 ICs being bridged.

    You forgot to attach the schematic and maybe a photo of the circuit you used.



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