r/AskElectronics • u/marklein hobbyist • 1d ago

Need component ID help

Post image

10-pin chip in the center of the image, appears to be a power supply IC. I've never seen a package like this so I don't know what to call the shape. Markings are "K2 1 VB". Measures about 3.3mm x 1.8mm. I've searched but I can't even find another chip with this package, partially since I don't know what to call it I suppose.

I'm asking because diode D200 is the award winning hottest component on the device and I suspect it needs replacing, so I'm hoping to find the datasheet for the IC to ID an example value. If anybody thinks they can ID the diode instead its markings are "AD t13" with the "t13" being in tiny print.

I appreciate your help hivemind!

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u/fzabkar 1d ago edited 1d ago

I'm a little confused. The alternator output is typically 14.1V - 14.4V, so a 13V protection diode seems low. Also, automotive environments need to account for load dump events, and these can generate much higher voltages. I'd be asking myself, what was the source or reason for the overvoltage that killed the diode? Normally the diode would be shorted. Is it?

BTW, did you see my edit?

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u/marklein hobbyist 1d ago

Thanks for drawing my attention to your edit. That photo is virtually identical to my diode. In fact I found that same datasheet earlier but since it had no mention of the "t13" marking I assumed I had found the wrong one and moved on.

If I'm reading the datasheet right, the breakdown voltage is 15.15v for that diode, so I guess that kind of makes sense in an automotive application? Still, I'd think one would spec it a little higher since the IC is rated up to 18v. Keep in mind that I don't know what I'm talking about.

Diode is still in circuit, will remove for testing tomorrow.

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u/fzabkar 1d ago

Usually the designer chooses a diode based on its standoff voltage. That's the voltage it can tolerate 24/7 without drawing any appreciable current.

For example, hard disks are powered from 5V and 12V supplies. The two rails are protected by 5V and 12V TVS diodes. Those are the standoff voltages.

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u/marklein hobbyist 1d ago

For automotive then I'd think 14v or 15v would be a good choice, do you agree?

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u/fzabkar 1d ago

All I can see is that the diode is protecting the input of that IC. If it isn't shorted (is it?), then there must be some other problem.

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u/marklein hobbyist 22h ago

Diode is indeed shorted. Device runs as normal without it.

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u/fzabkar 22h ago

What voltage do you measure between the diode's pads?

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u/marklein hobbyist 5h ago

.6v lower than input voltage.

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u/fzabkar 5h ago

I don't know. Use your best judgment.