First SMD PCB, non-inverting amp. LM358 is getting very hot

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Hi. I just etched my first smd circuit board and soldered all the components to it. It's a simple non-inverting amp design, but my op-amp is getting extremely hot! I've gone through my circuit several times, measured voltages, checking for shorts, resistances etc and everything is in place. I've tried two different LM358, but both of them heat up. I have nothing connected on the output and the polarity is not reversed, so how can an op-amp heat up like this (I burned my finger)? I was thinking that it was something with the 100uF decoupling caps, but I'm not sure if that can be the case (they don't have their polarity reversed either). Here's my circuit along with some pictures:

https://tangentsoft.net/audio/cmoy-tutorial/misc/cmoy-tangent-sch.pdf





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Just saw that the LM358 has a supply voltage range of 5.5V so that would explain it. This thread can be deleted.
 

??? LM358 has a supply range of 3V to 32V so that isn't your problem.

Those jack sockets have switches inside them, make sure you don't have them wired wrongly with the switch shorting the output of the amplifier. Also check that you have the same voltage (half the supply) across each of the 100uF capacitors.

Brian.
 
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    DrWhoF

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Picture nr.1 shows that the LM358 is mounted incorrectly - that is reversed by 180 deg.
The dot on its body indicates PIN1, not 5 ..
So, you have to replace it with a new one and solder the new one in the correct way ..
:wink:
IanP
 

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    DrWhoF

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??? LM358 has a supply range of 3V to 32V so that isn't your problem.
Click to expand...

I messed up. I was also under the strong impression that the 358 had a very wide voltage range, I didn't think that there were different types if 358. I have a LMV358: https://pdf1.alldatasheet.com/datasheet-pdf/view/9169/NSC/LMV358M.html
"The LMV358/324 are low voltage (2.7–5.5V) versions of the
dual and quad commodity op amps"
Click to expand...

Picture nr.1 shows that the LM358 is mounted incorrectly - that is reversed by 180 deg.
The dot on its body indicates PIN1, not 5 ..
So, you have to replace it with a new one and solder the new one in the correct way ..
Click to expand...

It's the correct way. The dot is pin 1, the output. As you can see it goes to a feedback resistor and then back to the inverting input. Pin 4 goes to V- (a trace under the op-amp) and pin 8 goes to +V (up to the outer contact of my voltage dividing resistors).


Good ting I bought 50 of these op-amps. Not only were they supposed to be NE5532 (no idea how I screwed that up), but they turned out to be low supply voltage 358 aswell :S No idea what to do with these now.
 

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