I was under the impression that the TDA 7293 and 94 are similar and that the only difference is that the 93 can handle higher voltage. And has a clip indicator.
Was also told that the chips are interchangeable i.e. if the circuit runs a 94 you can replace it with a 93.
So purchased a PCB for the 94. Built it and powered it up to test at very low voltage of 15-0-15 1 amp. Just to make sure nothing blows.
And it blew. No input or output was hooked up. Just the power supply. One unit exploded and one just got really hot. (Single PCB stereo setup)
After a few hours of study. Its apparent that the chips are not compatible. And that on the 93 you need to populate the boot strap part between pins 6 and 12. As well as adding a cap between pin 6 and output. A circuit that runs the 93 can run the 94 but a 94 circuit cant run a 93 this is what somebody told me.
Im now down to my last 2 93 ICs.
So thought I should check with you guys. Could this be the reason my chip blew ?. Or is it more likely that it was just a fake chip. The chip was sourced from Duabi. And I suspect the guys in Dubai sourced it from China.
Am reading up on the bootstrap most people recommend replacing the 22 uf cap between pins 6 and 12 with a 47 uf cap.
I have some TDA7294 ICs which look fake as hell but they work fine. Just cant find a source for good 94s so imported the 93s from dubai.
Any other tips for or common pitfalls that pop these ICs. As always found a wealth of info on this forum. Still reading up.
Found this link to be useful.
https://www.easybom.com/blog/b/tda7293-vs-tda7294-audio-power-amplifier-what-is-the-difference
https://en.wikipedia.org/wiki/Bootstrapping_(electronics)
Just trying to figure out if the lack of the boot strap components could result in the IC failing. If yes good. Will add the boot strap bits. If no then I have to start from scratch and recheck everything.
Was also told that the chips are interchangeable i.e. if the circuit runs a 94 you can replace it with a 93.
So purchased a PCB for the 94. Built it and powered it up to test at very low voltage of 15-0-15 1 amp. Just to make sure nothing blows.
And it blew. No input or output was hooked up. Just the power supply. One unit exploded and one just got really hot. (Single PCB stereo setup)
After a few hours of study. Its apparent that the chips are not compatible. And that on the 93 you need to populate the boot strap part between pins 6 and 12. As well as adding a cap between pin 6 and output. A circuit that runs the 93 can run the 94 but a 94 circuit cant run a 93 this is what somebody told me.
Im now down to my last 2 93 ICs.
So thought I should check with you guys. Could this be the reason my chip blew ?. Or is it more likely that it was just a fake chip. The chip was sourced from Duabi. And I suspect the guys in Dubai sourced it from China.
Am reading up on the bootstrap most people recommend replacing the 22 uf cap between pins 6 and 12 with a 47 uf cap.
I have some TDA7294 ICs which look fake as hell but they work fine. Just cant find a source for good 94s so imported the 93s from dubai.
Any other tips for or common pitfalls that pop these ICs. As always found a wealth of info on this forum. Still reading up.
Found this link to be useful.
https://www.easybom.com/blog/b/tda7293-vs-tda7294-audio-power-amplifier-what-is-the-difference
https://en.wikipedia.org/wiki/Bootstrapping_(electronics)
Just trying to figure out if the lack of the boot strap components could result in the IC failing. If yes good. Will add the boot strap bits. If no then I have to start from scratch and recheck everything.
Also you can't parallel 7294 like 93.
Yes they are interchangeable but as i said before 7294 is not made for parallel operation.
Directly from tda7293 datasheet~
For compatibility purpose with the previous devices of the family, the boostrap capacitor can be connected both between the bootstrap pin (6) and the output pin (14) or between the boostrap pin (6) and the bootstrap loader pin (12). When the bootcap is connected between pin 6 and 14, the maximum supply voltage in presence of output signal is limited to 100V, due the boot-strap capacitor overvoltage. When the bootcap is connected between pins 6 and 12 the maximum supply voltage extend to the full voltage that the technology can stand: 120V.
Did you insulated the chip from ground/heatsink before use?
Best regards
My understanding is that the back of the IC= - VS rail. So I can use a common heatsink without any insulation for both Left and Right TDAs As long as my heat sink is isolated from the case.
Have replaced the blown TDA and will chk for pin shorts and power it up one last time. I have been having **** luck with most of my purchases. Even the STKs I imported from the US turned out to be fake as hell.
Have replaced the blown TDA and will chk for pin shorts and power it up one last time. I have been having **** luck with most of my purchases. Even the STKs I imported from the US turned out to be fake as hell.
Yes, you can use common heatsink for both but i don't recommend that (it may act like an antenna). Anyway if you want to purchase genuine semiconductors buy from a reliable online store like mouser or digikey because in india we have very limited source.
Regards
Regards
Some tips I learned the hard way.
1. Go over the board using a cheap USB Microscope. You want to look for any cold joints and lead splatter. (I didn't find any).
2. Use a Multimeter and chk the values between ground and each of the pins. On the TDA. If its a stereo PCB it will help you catch any mistakes in populating both the TDAs. (Didn't find any difference).
3. If your building a 93 better to follow the 93 reference design.
Im waiting to get the isolating mica before I try round 2.
The PCB Im using is nothing but the reference design for the 94. Will have to run some jumper cables to make it compatible with the 93. And one cap.
1. Go over the board using a cheap USB Microscope. You want to look for any cold joints and lead splatter. (I didn't find any).
2. Use a Multimeter and chk the values between ground and each of the pins. On the TDA. If its a stereo PCB it will help you catch any mistakes in populating both the TDAs. (Didn't find any difference).
3. If your building a 93 better to follow the 93 reference design.
Im waiting to get the isolating mica before I try round 2.
The PCB Im using is nothing but the reference design for the 94. Will have to run some jumper cables to make it compatible with the 93. And one cap.