[sdiy] Making toast with chips

[Seb Francis]

I guess it depends how hot is hot :)

This webpage seems to say it's quite normal for 5532s to run "perceptibly warm when quiescent on +/-15V rails".  So I guess when they are also pushing a bit of current around they might run "hot".
http://www.dself.demon.co.uk/webbop/5532.htm

Looking at the datasheet, the standard tenperature rating is up to 70C which is quite hot.  I also notice the input bias current gets less as they get hotter - this is most likely not a bad thing.

Seb


Lincoln Fong wrote:

> Can anyone tell me if Opamps should ever run hot (to the touch) and what
> it implies if they are? I notice on some audio boards I'm looking at
> that the NE5532s (and 5534s) are hot to the touch. Some hotter than
> others. None of them is under much of an output load and the supply is a
> good quality +/- 15V fed in groups through fusible 4.7 ohm resistors
> that periodically blow. Each chip has a pair of 47nF ceramic PS
> decoupling caps right by it though they're 12 years old now. Am I right
> in thinking that the ones that are hottest to touch are the most likely
> to cause excessive current draw or is it a red herring? After all the
> boards don't give trouble 95% of the time- not a very good average I
> know. The odd thing is that usually replacing the resistor cures it at
> least for a while.
>
> I notice the hotter ones generally (though not exclusively) have a P
> suffix and are dual types while the cool ones are N suffix.
>
> Finally do some of you use some kind of (infrared?) thermometer to test
> ICs for symptoms of trouble? I would get one if this were the case. What
> would be a 'dangerous' temperature?
>
> Lincoln
> _________________________
> Lincoln Fong
> http://www.fongelectronic.com