any op-amp recommendations?

I'm getting ready to order some junk from Digikey. Can someone
recommend good general purpose op-amps to stock for tinkering? I've
been using the 741 just because I had a few laying around, but I know
that better things exist. I've also got a couple of TL082s, but really
haven't done much of anything with them yet. The 741 has worked ok
(more or less) for me, but I want something with better gain at 40kHz
(ultrasound tinkerings) and that can go much closer to the rails since I
like to use 5V for power. Something that won't easily latch up would be
nice too. I don't need anything really fancy, just something relatively
inexpensive ($2 or so) and easy to use. BTW, I like to use solderless
breadboards for prototyping.

For comparators I use the LM393, is that still a reasonable choice or
should I stock up on something newer?

TIA

 

Anthony Fremont wrote...

My vote, for +/-15V supplies, is the LM412 dual JFET opamp.

 

OPA134 for a traditional OP-AMP. Single version.Think of it
as a really beefed up TLO81. Power bypass caps are necessary
for high speed amps.


greg

 

I'd worry about the OPA134 in a solderless breadboard.

 

I'm wondering if that's a typo and you mean LF412?

I too have been on the lookout for an inexpensive general-purpose
op-amp, but with higher input impedance than the 741.

Thanks,

Mark

 

redbelly wrote...

Yes, sorry.

Right.

 

LM393 the best price/perfamance comparator ever made.

 

Thanks. Any recommendations for something in the 5V single supply
arena?

 

Thanks. I looked at the datasheet and it seems like a real nice
part especially for audiophile applications. Fast and really low
distortion, but it sounds like it may be a bit wild for the breadboard.

 

I've prototyped a lot of circuits with OPA134 in solderless breadboards; no
problem. It's not really blazingly fast - good audio opamp but not the sort
of thing that will get you in trouble.

However, it's rather expensive as a "jellybean" opamp. I usually prototype
first with something cheaper, e.g. TL08x, and then plug in the OPAx134 at
the end.

 

Cool, I guess I'll stick with them then.

 

For 5 volt supply, I like the MCP6022-I/P, dual, rail to rail, 10 MHz
GBW product (gain of about 250 at 40 kHz), made by Microchip, the
people who make the PIC microprocessors. Digikey sells these for
$1.80 each.

http://rocky.digikey.com/WebLib/Microchip/Web Data/MCP6021,2,3,4.pdf

But a good, cheap jelly bean amplifier for low frequency use is the
dual LM358. Works from the negative rail up to 1.5 volts below the
positive rail. About $0.50 each.

I still use lots of those and the quad LM339, also.

 

Way cool! I think I'll buy me a few. The chip select feature is
pretty nice and I like that cute Vref available on a couple of the
sibling models. I couldn't find anything in the datasheet on how much
of a drain the Vref added on the power supply, but with total quiescent
current at about 1mA, who cares. ;-)

I'll look at the datasheet, but the microchip op-amp looks like it just
might be the one. Thanks again.

 

GregS wrote...

I don't like getting into bed with an opamp with no schematic.

 

LF412 ?

Odd choice. Hardly ever see it in commercial kit. Well, never actually.

TI's TL series of bifets would make more sense.

Graham

 

For rail to rail apps (in and out), I love the TI TLV237x family.

-- Andrew

 

I think it time to move to micropower op-amp and dispose +/-15V or
+/-12V (unless you really really need it). I work on +3.3V and +5V
schematic with various rail to rail op-amp, the performance is pretty
good nowaday, especially low noise just released by LT. It also easier
to interface with digital circuit. I use ADR361 for voltage reference
source as midway.

Good luck

 

Avoid Advance Linear Device...the op-amp range is really crap!

 

Thank you for mentioning them, they look like just the thing for my
purposes (home hobbyist, low frequency analog stuff, such as
photodectors and thermal measurements).

Mark

 

Riscy wrote...

What do you mean by "range" and what do you mean by "crap"?