opto couplers

[Rene Schmitz]

At 23:07 01.07.1997 +0200, you wrote:
>Hi all,
>
>The last couple of weeks I'm busy making a midi interface with a
>PIC16C73, for one of my analog synth projects.
>The opto coupler I used in the first place was a CNY17-2 from QTC, which
>didn't work properly. After measurements I found out that this one was
>just to slow, because the rise and fall times at the transistor side
>were too long.
>After that I used the same type but from an other manufacturer (HP I
>think). This opto worked well.
>
>My question is, which (low cost) opto is mostly used for midi
>applications? Maybe the CNY17-2 isn't really suited for this kind of
>stuff.

I used the CNY 17-II and had (yet) no problem.
But I had the idea to use the phototransistor along with an ordinary
tranny in a cascode circuit, this should minimize the rise and fall times.
(No there is nothing against a PC900 or something else to use here, 
but I thought I might share this idea.)

Bye 
 Rene