LM3900: LM3900N

Plugging the most important parameters into the search function gives few results.

If your circuit does not actually require the full range of these parameters, then there are likely to be more possibilies. On the other hand, if your amp is designed for Norton amplifiers, you cannot replace them.

Hello Michael,

There are many modern operational amplifiers that could be electrically substituted for the LM3900N, but the problem is its very unique pin plan and the older DIP package that isn't used for newer devices. 

The LM3900N is still produced by TI and should be available through our distributors so you shouldn't have any problems obtaining the device.

Regards, Thomas

Precision Amplifiers Applications Engineering

It was used in the 4 Channel Phase Linear 4000 I Autocorrelation Preamplifier. LM3900N appears on three of the 13 boards, one on low amp, two on the PLO7C board and one on the PLo9B BP1 board. It is note worthy that this IC has been made for ~ 45yrs and TI has only one other version LM3900NE4. ON Semiconductor a group of posable candidates but will by no means make a call.

Hello Michael,

Sorry.. I had to delete my previous post and did not want to confuse. That appnote was about the LM359  (very similar).

The *correct* original LM3900 appnote is AN-72:

 The LM3900 A New Current-Differencing Quad of Plus or Minus Input Amplifiers

More than you probably wanted to know...:^)

LM3900's were very popular for audio applications, particularly VCA's and VCF's in organs and "analog" audio processors - so it is no surprise you see them in an old Audio application.

Hello Thomas,
Yes, I know LM3900 is still available, both in N and NE4 variations, and the LM3900N's I'm holding in my hand are at least 45yrs old, because they came out of a Phase Linear 4000 that was manufactured in 1973. The after market does have adaptors for some Dips, if you know of a better IC that will do the trick, I may be able to find the a Dip adaptor.
Regards,
Michael

Hello Michael,

I searched the web for DIP adapters that would accommodate modern dual and quad SOIC packaged op amps. The LM3900N pin out is so unique I didn't find any DIP adapter that would work. I thought the old TI RC4136 quad op amp used the same pin out, but it turned out to be unique as well. That device actually does have a dual SOIC to DIP adapter available from Cimarron Technology. There may be one out there for the LM3900N.

Assuming you are able to come up with an SOIC to DIP adapter having the LM3900N pin out, an example of of a modern precision op amp that will provide very high performance is the OPA2196 (dual) and OPA4196 (quad). You can find the datasheet here:

A quick comparison of the LM3900N and OPA4196 electrical specifications is provided here:

I hope this helps.

Regards, Thomas

Precision Amplifiers Applications Engineering