CA3094------->LM13700 (microsynth)

[alecacca]

hi!!
i see a topic where someone says that CA3094 can be replaced with a lm13700...
but i have a problem, how i must wire the 13700 for use it like the CA3094?
sorry for the bad english,   -alex

[Thomas P.]

a look at both datasheets will help you get along 

[alecacca]

thanks tom, but i have looked at the datasheets, but i don't know hot to "connect" the pins... 
in the ca3094:
1-ext. frequency compensation or inhbit input
2/3- differential voltage input
4- GND or V-
5-I abc current (programmable input)
6- drive output ( emitter )
7- V+
8- sink output ( collector)


in the 13700:
1- amp bias input
2-diode bias
3-input +
4-input -
5- output
6- V-
7-buffer input
8-buffer output
11- V+

[Thomas P.]

in the CA3094 the outputbuffer is internally connected to the OTA's output (pin1) while in the LM13700 the outputs of the OTA's are pins 5,12 and the buffer inputs are pins 7,10

maybe the buffer connection needs to be altered since the LM13700 has the collectors of the darlington connected to V+, but that depends on the setup. If the "sink" output (pin7) is already connected to V+ then it's cool

[alecacca]

in the schematic 4 of the CA3094 have the collector connected to V+ , but in 2 of them the collector is sconnected...

[RaceDriver205]

If the lm13700 doesn't work out, you can try the ca3080, which can be converted to a ca3094 with a darlington.

[alecacca]

here the CA3080 is hard to find like the 3094....
and where i must put the darlington?....   thanks guys!   

[RaceDriver205]

Oh, it was in a post I did a little while ago. But if you can't get them then it doesn't matter I guess.
Note that futurlec.com still has them fairly cheap, if its possible for you to mail order.

[Thomas P.]

I took a closer look at the schematic and it appears that the CA3094 would be best substituted by CA3080's with a darlington pair at the end! That is because at least two of the are connected without the buffer (I think the squarewave shaper and the one right in front of the SVF) so they could be replaced by a plain CA3080!

[trevize]

guarda lo small stone di tonepad ale

Look at tonepad's small stone. Francisco did this substitution.

[Thomas P.]

guarda lo small stone di tonepad ale

Look at tonepad's small stone. Francisco did this substitution.

I'm aware of that! The reason I posted this is because some of the CA3094 can be substituted by CA3080 directly!