Commercial (Alpine PDX) Class D Failure Pics and Question about IR2010s

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Here I have a failed Alpine PDX 1000.1

If you are not familiar with it, it is a compact Class D car subwoofer amplifier. It's specs say it will drive 1000Watts into a 2-4 ohm load. I didn't find it to do quite that, but it is a nice package. It failed the other day while I had the input muted. It was in a hot trunk, and started by drawing a large pulsing current from the vehicle - enough to make the entire car dim a couple times a second. I did not hear any output from the sub (8 ohm), but it could have been so low a frequency that it was inaudible. The car is not particularly quiet. I turned the input power off, and back on - it blew the 4x20 amp fuses on the board.

Anyway - after taking it apart I found that an International Rectifier driver IC IR2010s (one of two) had popped it's top. I know nothing about class D design, but generally when I see something like that I assume there is another problem which cause a driver chip to let it's smoke out.

You guys being knowledgeable on Class D stuff and probably familiar with this particular family of chips - tell me, should I replace the chip and see what happens? ( I am not fond of working on electronics that have this kind of current capacity) or is it most likely fried and I should just set it aside.

Thanks
 

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Joined 2005
If the driver chip went kaput you should also check the surrounding parts to verify that they're still ok before just replacing the part and powering it up again. In particular, check to make sure the output mosfets aren't shorted out (which is highly likely).
 
That's what I was thinking too. The attached picture is apparently the output section. I have no idea how to remove/replace these things. I don't even know what package they are. I am thinking they are a BGA mount?

I can check the power supply fets, but the outputs are a mystery to me.
 

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Alpine Class D

I work with a car audio manufacturer and we blew up ours on the bench. Turns out this amp has a so-so reliability reputation. And a blown 2010 does indicate bad FETs.

What the ICE power rep told me when I tried to buy some of the ICE chips, problems with this amp has led ICE Power to take all car amp design in house and they now only sell the chips if they can engineer the entire product.

They sell me ICE modules but the chips are only available as parts of modules or complete designs from them.

Too bad. It was a nice looking amp.
 
Direct FETs

It is very difficult to replace these FETs. We work closely with IR and we use their IRS20955 chip BUT we do not use their diect FETs.

The reason is, all are low current and only available in 100v in quantity (We build 1,000 amplifiers per month so we use lots of Mosfets)

The IR2110 chip blew due to bad mosfets and there is NO way to protect the chip from failure in the event of Mosfet failure.

The IR2110 chip is a relativley slow chip and works well up to 100KHz. I do not know what the oscillator freq in this amplifier is.

My opinion, the time and trouble needed to repair this amplifier ---- go and purchase a new amplifier.

Stephen Mantz
Zed Audio Corp.
 
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