Direct substitute of CA3080....

[paku5535]

hello guys,

Can i directly substitute ca3080 with LM13700 by taking appropriate pin(Pins of CA3080)? Or any modification require?? Actually I had one piece of CA3080, Which I burnt in short circuit and After making PCB i cannot even check whether the circuit is working properly...The only available chip is National LM13700...

Thank you

[Kesh]

I'm guessing you read http://www.idea2ic.com/LM13600/UsingOTAs2.pdf which says it is a replacement but dual version and with bias diodes which you can leave unconnected.

[R.G.]

If you ignore the distortion reduction diodes and the diode buffers, yes, it operates much the same way in a circuit. However, there is one other issue. The Iabc pin on the CA3080 will always be at one diode drop (0.45 - 0.7V) above the most negative supply pin. In the LM13700 and all other later OTAs, the current mirror input will sit at two diode drops (0.8 to 1.4V) above the most negative supply. In most circuits this makes no difference at all. However, there are some limited situations where it would make a difference.

But you're right, you are stuck with figuring out how to make an LM13700, NE5517, or CA3280 work.

[paku5535]

yea RG.....

thanks RG and Kesh for your reply......