I have a bunch of IL388 if you need them (on my webstore) -- but they are pretty readily available from 5 or 6 distributors at least in the 'States.
I used analog optp-couplers for a HV supply as well. The IL388 is faster than the IL300 or HCNR200/201.
Whether they are suited to audio is a question I never pursued. I just ran triangle waves with them to check the linearity, and they suited my purpose well.
I used analog optp-couplers for a HV supply as well. The IL388 is faster than the IL300 or HCNR200/201.
Whether they are suited to audio is a question I never pursued. I just ran triangle waves with them to check the linearity, and they suited my purpose well.
lineup, if you use optos where the transistor base goes out to one of the package leads (most do if they have 6 pins, but obviously the 4 pin ones don't), you can pre-bias the base for operating point. another option would be to make your own optos with an IR LED and a phototransistor, and add a high Vce transistor buffer. i kind of like the concept, especially the direct from the diff amp drive. no need to play with VAS compensation because the diff amp doesn't need to charge a cap.
It would be nice if it worked, but let's take one problem first:
A LED does not emit light that is proportional to the supplied voltage.
Stinius
A LED does not emit light that is proportional to the supplied voltage.
Stinius
stinius said:
The analog opto-isolators like the HCNR-200 have a pair of diodes on the sending side -- so you can correct on the fly -- see the applications on Agilent's website:
http://cp.literature.agilent.com/litweb/pdf/5989-2137EN.pdf
Avago (son of Agilent, ergo grandson of Hewlett Packard) also has some nice application notes ontheir site, in particular app note 1078 "Designing with Avago Isolation Amplifiers".
Thank you, I have been looking for a component like that, for another purpose.
Have you tried it?
They don’t show how the output is tracking the input, for different frequencies and waveforms.
Stinius
Have you tried it?
They don’t show how the output is tracking the input, for different frequencies and waveforms.
Stinius
And by the way jackinnj, it’s a lot of moose here in Norway. It is the hunting season now and a friend of mine shot one today.
You probably don’t have moose in New Jersey?
Stinius
You probably don’t have moose in New Jersey?
Stinius
stinius said:
but they do emit proportional to current, which is what the output of a diff amp is, current.
there is nothing much to explain...it's just a weird idea with no practical use 😉darian said:
regards
stinius said:
We have moose in NJ, they are all females...they either belong to the Rosary society, or play mahjong... tous la meme chose in my corrupt french.
The multisexual moose are in Maine and they are mean critters.
Here in Whitelandia we have moles, chipmunks, squirrels, racoons, possum, badgers, wild turkey, coyote and deer.
just a quick glance through a Newark catalog yesterday. there are some very linear optos out there some claiming a -3db bandwidth of 100khz.
The idea.
By using fast analog optocoupler
transfer the two currents
from one differential input
to the bases of two identical NPN outputs.
There has been some talk of N-Channel as only true complementary.
But in a quasi stage you use at least one driver PNP
which interact with lower NPN.
Using optical coupling is one way around
and to get a true N-Channel amplifier.
Using transformers is another.
By using fast analog optocoupler
transfer the two currents
from one differential input
to the bases of two identical NPN outputs.
There has been some talk of N-Channel as only true complementary.
But in a quasi stage you use at least one driver PNP
which interact with lower NPN.
Using optical coupling is one way around
and to get a true N-Channel amplifier.
Using transformers is another.
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