Sure IR2092 2x250W Overheating (plus bus pumping when idle)

[nigelwright7557]

I added space on my 2092 pcb for resistors across the smoothing capacitors but in normal practice found I didn't need them.
I found the only time I got bus pumping was when using a signal generator and low frequencies.

 

[David_Web]

Not sure what the capacitance or the VA rating is, but I can check the ripple with a scope when I pull it apart again.

Here is a thread with comparison against reference:
http://www.diyaudio.com/forums/clas...e-ebay-sure-electronics-2x250w-class-d-2.html

Dead-time is probably not correct set as others have reported the amp running hot even with lower rail voltage:
http://www.diyaudio.com/forums/class-d/220281-sure-electronics-irs2092-250wpc-amp-build-4.html
I did adjust the frequency from default 180kHz (IIRC) to 400kHz but that did not make much of a difference as it got too hot to touch anyway. I didn't time how fast it heated up so I can't compare that.
The output waveform also have spikes in it at crossover. Which to me would indicate dead-time issue.

So I would still like to know what would happen is 105ns turns out to be too long dead-time.

 

[ungie]

Not sure what the capacitance or the VA rating is, but I can check the ripple with a scope when I pull it apart again.

Here is a thread with comparison against reference:
http://www.diyaudio.com/forums/clas...e-ebay-sure-electronics-2x250w-class-d-2.html

Dead-time is probably not correct set as others have reported the amp running hot even with lower rail voltage:
http://www.diyaudio.com/forums/class-d/220281-sure-electronics-irs2092-250wpc-amp-build-4.html
I did adjust the frequency from default 180kHz (IIRC) to 400kHz but that did not make much of a difference as it got too hot to touch anyway. I didn't time how fast it heated up so I can't compare that.
The output waveform also have spikes in it at crossover. Which to me would indicate dead-time issue.

So I would still like to know what would happen is 105ns turns out to be too long dead-time.

I would simply populate the correct DT resistor values from the ref design datasheet and see if the heat decreases. Looking at the links you provided I would also install the correct current protection resistor values.

 

[David_Web]

Got the sub back today.
The smell when I opened the sub up told me something bad happened.
Driver is toast with scraping and shorted coil. Main fuse into the sub was tripped.

So not exactly impressed.

 

[doru76]

i have the same amp from sure and i had overheating problems but I've solve them by adjusting the 2 pots to ~ 256ohm, i found that info here: http://www.diyaudio.com/forums/class-d/220281-sure-electronics-irs2092-250wpc-amp-build-4.html#post3620312
now the amp runs warm to hot but not burning hot, the only things burning hot are the blue resistors

 

[David_Web]

Ill have to check if the channel I disabled is fine. It could have been a defective transistor on the channel I used that caused the excessive heat, and the destruction of the sub.

It doesn't go into oscillation now and draws almost no power, so something happened.