Urgent - LM1458

[Alan Smithee]

Hi all,

I need a alternative to the Dual Op Amp LM1458

MC1458CN OK?

NE5532N ??

Please help - need to get this thing done really quickly

Oh - here's the circuit diagram I'm using

http://ourworld.compuserve.com/homepages/Bill_Bowden/page4.htm#whistle.gif

Thanks

 

[Ben Bradley]

In sci.electronics.design, "Alan Smithee"

Hi all,

I need a alternative to the Dual Op Amp LM1458

MC1458CN OK?

NE5532N ??

Please help - need to get this thing done really quickly

Oh - here's the circuit diagram I'm using

http://ourworld.compuserve.com/homepages/Bill_Bowden/page4.htm#whistle.gif

Most any op-amp, whether dual in one package, quad in one package,
or two singles, will work in this circuit, as long as the max power
supply voltage ratings is less than the +V and -V values. The 5532
will work but it's overkill. but you should put a 5k or so resistor in
series with the wiper of the 25k pot. The 5532 has internal diodes
across the + and - inputs, and if the pot were turned up to the output
side with more than half a volt acrosss the output cap, it would dump
a lot of current into the diode and burn it out. Other op-amps might
not like their inputs going above their positive supply, either:
there's no voltage given for +V and -V, and if the out voltage is
greater than +V and the pot is turned up, the - input could go above
the +V op-amp supply.

Thanks

Hey, aren't you a famous film director?

 

[Alan Smithee]

Thanks very much - situation is now resolved

Hey, aren't you a famous film director?

Yes, but I'd rather not talk about it

 

[Walter Harley]

I need a alternative to the Dual Op Amp LM1458
MC1458CN OK?
NE5532N ??

Please help - need to get this thing done really quickly

Oh - here's the circuit diagram I'm using

http://ourworld.compuserve.com/homepages/Bill_Bowden/page4.htm#whistle.gif

Ben is quite right that essentially any dual opamp will work.

Myself, if I were building that circuit and had the luxury of choice, I'd
look for an opamp with low DC offset and low bias current, to improve
accuracy. But myself, I wouldn't build that circuit in the first place.
Instead, I'd probably use a variable regulator chip, such as the LM317:
better reliability, fewer parts. If I wanted the adjustable current
limiting I'd keep the "bottom" part of the circuit, although I'd probably
use a comparator instead of an opamp.

But you say you're in a big hurry, so the answer is "use whatever you've
got, it don't matter".