[sdiy] Opamp compatibility questions

[James Patchell]

At 02:08 PM 5/2/2005 -0700, Kevin Lightner wrote:
>>Hello list
>>
>>I have a few questions about some "older" opamps and
>>possible pin compatible substitutes, prefereably in the
>>TL0xx series, as i am stocking them already, but anything
>>modern will do.
>>
>>1) What is the difference between NE5534A and Ne5534AN ? and
>>is there a reason that a circuit should use one of each for
>>what looks like very similar pre. amp. tasks ?
>
>I think they're the same, but maybe someone will correct me.
>Possibly a different grade.
>
>>Any pin compat. subs for these ?
>>
>>
>>2) Any pin compat. subs for Ca3140E ?
>
>Not that I know of.

         Depends on what you call pin compatible...for general purpose use, 
a TL071 will sub for a CA3140...however, generally when I design a CA3140 
into a circuit I am looking for high input impedance and very low input 
bias current...




>>3) Am i correct in assuming that TL084 can substitute LM348
>>?
>
>Not always.  Some circuits want that same FET input.
>
>>4) Any pin compat. subs for LM324 ?
>
>TL075? (I really don't recall)

         The TL074, TL084, TL054...etc all have the same pinouts as the 
LM324....however...doing a straight sub can be tricky...generally, when I 
use the LM324 in a circuit, I am taking advantage of some of it's 
characteristics, such as an output that can go very close to the pin 11 
voltage, and an input whose common mode input range can go a bit below the 
negative rail....but in general, you can interchange these devices...




>>5) Any pin compat. subs for LM1458 ?
>
>Tons.
>Even the 4558 is an overall improvement.
>
>
>--
>Regards,
>Kevin Lightner
>
>http://www.synthfool.com

         -Jim
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