NE5532 Harmful oscillation

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
They will be fine if from Farnell. So you need to do some basic tests. If its getting really warm then check the current consumption... 5532's do get a little warm. And you really need to use an oscilloscope to see what is actually happing.

If the chip is really hot within seconds then something drastic is occurring.

The output buffer is shown as inverting... so the + input needs to be ground referenced.

The first diagram looks OK but as a test, if you isolated the four caps then it should 100% be stable. If it still got hot and didn't work then you have to suspect the opamp.
 

silverprout

Member
2008-04-03 4:19 pm
They will be fine if from Farnell. So you need to do some basic tests. If its getting really warm then check the current consumption... 5532's do get a little warm. And you really need to use an oscilloscope to see what is actually happing.

If the chip is really hot within seconds then something drastic is occurring.

The output buffer is shown as inverting... so the + input needs to be ground referenced.

The first diagram looks OK but as a test, if you isolated the four caps then it should 100% be stable. If it still got hot and didn't work then you have to suspect the opamp.

Oups:rolleyes: sorry, here is the good sheme of my output buffer.



I will make some measurements soon but the thermal runaway is fast... i must physically prepare myself to be fast :Popworm:
 

silverprout

Member
2008-04-03 4:19 pm
Yes.

We don't often write how it can be fun to make circuits and experimentations :spin: and it is fun really sometimes :D

the circuit is stable and the gain is ok ! (was not with the TL072) with a 220pF styrofex cap soldered directly on PCB tracks and very close to the chip.

:D now the ASP board is equipped with MKS, MKP, MKT, NPO and Electrolytic caps:D

I've forget Tantalum :rolleyes: