Hello Folks,
The LP324 is the really low power version of the old work horse LM324. Unfortunately it doesn't come in dual, only quad, meaning the LM358 doesn't have a low power sister. Other contenders such as the OPA2244 are just plain too expensive.
Is there a dual low power opamp,
Have you looked at the LPV358?
Have you seen:
'Single supply' means ground referencing capable inputs ?
How about slew rate, noise and bandwidth ?
I'd have though any of TI's CMOS op-amps might be a contender.
Graham
Many, if not most, of the new ones won't handle Joerg's 25V supply requirement. Same deal with the LMV822.
The good old TLC27L2 comes close- but 16V max supply.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
I seem to find I often spend ages looking for the op amp I need, I wish there was a more usefull list somewhere, I use the farnell parametric selection table a lot, but often later find i missed one that didnt show up becuase one of its attributes wasnt listed in the table.
At the moment Im looking for a dual op amp 400ma rail to rail op >=10v/us
10v supply, and also a cheaper alternative to the opa2354 (wich is a very nice part)Colin =^.^=
Is there anything worser than an LM324??
Jorgen
Hello John,
That one maxes out at 5V and would fry in this app.
Thanks! I scoured TI yesterday and it did not show in the list. Even keyed it into the search and pulled a blank while today it did pop up. TI seriously needs to "de-sophisticate" their site. It's going towards more glitz and less content. Or they should maintain a bare bones portal for engineers.
The problem with the LP358 will be to purchase it. Digikey, Newark and Mouser don't carry it which is not a good sign at all. Arrow does but shows no stock, not a good sign either. Could be close to unobtanium :-(
Regards, Joerg
Hello Graham,
Yes. But outputs don't have to be RR, not even to ground.
Absolutely not critical here, can have the reaction speed of molasses. Offset isn't a challenge either, anything under 15mV goes.
I found a few but those were way too expensive.
Regards, Joerg
Hello Jorgen,
There is. But what's wrong with it? I have designed in oodles of these and had no issues whatsoever. It's a fine work horse chip at very little cost. Costs around 10c in large qties which means you pay 2.5c per amp. Hard to beat, isn't it?
Not every task is a cost-does-not matter taxpayer funded project. Sometimes, or in my case most of the time, cost is paramount in a design.
Regards, Joerg
Perhaps the 741. The question is less, how bad it is, but rather what you can achieve with it. National Semiconductors and such are happily selling you a tweaked fet input, zero drift, low noise, RRIO OpAmp for thirty times the price.
Rene
-- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net
Hello Rene,
When I was young I preferred the non-compensated ones. Same price but a lot more gusto. Of course, these designs needed to be treated with great care and respect or it would all oscillate like crazy. Most of the time I shunned opamps altogether because it didn't feel right to pay a Dollar for a wimpy uA709 where I could achieve better results with 25c worth of transistors and parts.
After successfully doing a clamp-based zero-drift with ye olde LM324 that feels like winning the world cup. Oh, and I made a switch mode supply with one. Actually, only a quarter of one.
All this reminds me of neighbor's and co-worker's comments after I bought my car, a Mitubishi Montero in the absolute bare-bones version. "Ah, but that's not a V8 and doesn't even have central lock or power windows". Thing is, I paid only half of what they paid and get twice the fuel economy. Nowadays where crude oil is over $60/barrel there are some who wish they hadn't bought their luxurious Durangos.
Regards, Joerg
"Joerg" skrev i en meddelelse news:km7Ef.40762$ snipped-for-privacy@newssvr21.news.prodigy.com...
That some versions of it will slam rail-to-to rail pulses out when common mode crosses zero - if one naively uses it as a sense amplifier f.ex. not all, some parts.
Hello Frithiof Andreas,
You have to remain within data sheet specs, can't go below zero.
Regards, Joerg
You can go below zero, just not too much below zero.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
I sometimes wonder about that when I see the lower limit quoted as exactly zero in the datasheet ("Vss", whatever). I always suspect that if it works all the way down to zero, then surely it can go a *little* bit lower before something bad happens!
-- John Devereux
Hello Spehro,
Yes, note 10 in the LM324 data sheet states 300mV although I'd never dare to go that much below. The input devices Q1 and/or Q4 could lose Uce head room and that's when the nasty surprises loom. But one can't blame the opamp for that.
Regards, Joerg
Hello John,
Look at foot note 10 in the data sheet. It states 0.3V below. Too much for my taste though.
Regards, Joerg
Why? It IS silicon after all.
...Jim Thompson
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| James E.Thompson, P.E. | mens |
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| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
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Anyone can be rude, but it takes a Democrat to be a real dirtbag.
Hello Jim,
Yes. But Q1 and Q4 need a little margin for Uce.
Regards, Joerg
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