LF357 stability

[richwalters]

Hi there

.....This chip is a high flyer...anyone successfully used an LF357...it's output circuit is particulary attractive...
What's the best circuit configuration with this ic.. invert/non invert ? .....I thought I had it sussed .....but it was oscillating peacefully into the SW.....any thoughts ? The compensated 356 is way easier to use...but slower...

richj

 

[peranders]

This opamp requires a gain of _minimum_ 10 => not suitable for buffers, tone controls etc.

I used this opamp in the early 80's just because my suppier had run out of LF356. I used this LF357 in an equalizer and I used the frequency compensation according the datasheet but I never got it working properly.

Conclusion: Use LF356 for buffers, tone controls etc.

 

[richwalters]

I used this opamp in the early 80's just because my suppier had run out of LF356.

Conclusion: Use LF356 for buffers, tone controls etc.

Umm........thanks for reply.....that makes two of us of the same opin. It strikes me that the DiL 8 package creates the worst of 2 poles....as you said the 356 is pretty tame......
I find the thd pretty sim to TL071 series and suprisingly the noise of the compens 356 is finer grass......I'm using this op amp as a driver in my headphone amp as it can drive better than TL series.

richj

 

[peranders]

It strikes me that the DiL 8 package creates the worst of 2 poles....

This has nothing to do with the package really, it's the silicone chip. LF357 is an old design and they could do each stage fast enough.