I hate LM324 !

[Arkham00]

I admit that this thread title is just to get attention and suggestions from Audioguru, that hates LM324.

I too hate LM324 but ... but it was a nice device at its times. A lot of years has been passed and now I think we have much better devices so I wanted to know some op-amp that have the features to become famous and used as the famous LM324. I've done some search on electro-tech and in other places (this is a quite common question) and this is a list of devices that I think could substitute LM324 as a general purpose, signal conditioning op-amp for PIC/AVR based designs.

I limit my search to devices with quad amp, PDIP package, rail-to-rail in input/output, low single power supply voltage, low price. Here is what I've found till now:

• MC34074 (OnSemi) - V=3/44, GBW=4.5MHz, Bipolar (no R-R)
• MC33174 (OnSemi) - V=3/44, GBW=1.8MHz, Bipolar (no R-R)
• MC33204 (OnSemi) - V=2/12, GBW=2.2MHz, Bipolar
• TLV2374 (TI) - V=3/16, GBW=3MHz, CMOS
• TLC274 (TI) - V=3/16, GBW=1.7MHz, CMOS
• TLV2464 (TI) - V=2.7/6, GBW=6.4MHz, CMOS
• LM6134 (NSC) - V=2.7/12, GBW=10MHz, Bipolar
• LMC6484 (NSC) - V=3/15, GBW=1.5MHz, CMOS

Do you know other devices to add to the list?

 

[Hero999]

It depends on what you're using it for.

I use the TL074 for audio and the MC34074for general purpose.

 

[Oblong]

The best BW to supply current OP I’ve used is the LMV641.
Is -220uA worst case
GBW-10MHz
Vos -700uV worst case
Reasonable price.

The LMV116 is pretty good too.

signal conditioning op-amp for PIC/AVR based designs.

Microchip makes several RR in/out OP’s.

I still use the 358 series to they are dirt cheap if they can do the job I’ll use them.

But like was already said op-amp selection depends on what your application is.

 

[Speakerguy]

All else being equal I choose TI devices. I did a lot of prototype work at an R&D job and it's really helpful to be able to get samples overnight for free from TI when your supplier is out of stock. TI got designed in to a lot of our stuff because of their sample and support policies.

Also, the TLV2461 (dual version of TLV2464) was our standard signal conditioning op/amp for temp sensors etc when we needed to interface them to an ADC on a PIC.

 

[audioguru]

The LM324 quad opamp is not R-R input and is not R-R output.
Most opamps are not.
Why do you want rail-to-rail?

An LM358 dual opamp has a lot of noise, it has a lot of crossover distortion and its bandwidth is only to about 1kHz at 28V p-p. It costs $.40 today. The better LM358A costs less today.

A TL072 low noise, low distortion and wide bandwidth (100kHz) dual opamp costs $.64 today.

 

[duffy]

Is the the LM324 hate club? Excuse me, I think I see my seat over there. Oh, is it my turn to testify?

The LM324 sucks. It is the filthiest, disease-riddled piece of silicon ever to insult common sand with it's presence. I once was lured into putting one on an opto. Just an ordinary opto.

"Say Duff, there's no problem if we increase the switch matrix read speed from 'adequate' to 'ludicrous speed', is there?"
"Heck no."
"Say Duff, we can read all the switch matrix except your stupid ugly pee-pee doo-doo optos."

 

[arhi]

ok, here I am with my idiotic questions about op amps, audioguru sorry in advance, but I'm not embarrassed to ask when I'm in doubt ...

what the heck RR (rail to rail) means for the op amp?!?!

I was making some circuit other day and used mcp602 it works as expected and that's the first time I saw "rail-to-rail output" .. I have no idea what that means any "simple" explanation and what is the other type of output (when it is not rail to rail what it is then?)

 

[audioguru]

The LM324 was revolutionary when it was introduced in about 1970.
1) It is low power. (that is why is is very slow, has noise and has crossover distortion)
2) It operates with a supply voltage as low as 3V. (So what?)
3)It has inputs that operate at the negative supply voltage so it doesn't need a negative supply voltage.

The MC3317x are single, dual and quad opamps. They have the same low supply current as the lousy old LM324 and LM358, also operate from a single supply as low as 3V, also have inputs that work at the negative supply voltage but have no crossover distortion and have a bandwidth 35 times higher to 35kHz.

The MC3407x are also single, dual and quad opamps. They have normal supply current, also operate from a single supply as low as 3V, also have inputs that work at the negative supply voltage but have no crossover distortion and have a bandwidth that is 100 times as much as the lousy old LM324 and LM358 opamps.

There are many other good opamps.

 

[duffy]

From the positive supply to the negative supply, arhi. The "rails" were the rails of ladders. Relay ladders. Still in every circuit, just jagged and invisible now.

 

[arhi]

duffy, clear ... so if it is not R-R then it is R*X - R*X where X<1 ? hah .. it was soooo simple thanks

 

[audioguru]

what the heck RR (rail to rail) means for the op amp?!?!

Ordinary opamps have complimentary darlington emitter-followers at their output. So the max output voltage is about 1.2V less than the positive supply and the minimum output voltage is 1.2V more positive than the negative supply.
But a Cmos R-R opamp has an output that goes to the supply voltages when the output current is low. The output goes to the "rails".

Ordinary opamps like the lousy old 741 have inputs that work only if they are about 3V less than the positive supply and 3V more positive than the negative supply.
The LM324 and LM358 have outputs that work at the negative supply voltage but do not work if they are higher than 1.5V less than the positive supply voltage.

Some opamps have inputs that work at the positive supply voltage but the opamp goes crazy if an input goes lower than 4V above the negative supply voltage.
But a R-R opamp has inputs that work fine at either supply voltage. The input goes to the "rails".

 

[arhi]

thanks for the great explanation

 

[blueroomelectronics]

"Say Duff, there's no problem if we increase the switch matrix read speed from 'adequate' to 'ludicrous speed', is there?"

Good thing you didn't go to plaid.
**broken link removed**

 

[Ubergeek63]

Is the the LM324 hate club? Excuse me, I think I see my seat over there. Oh, is it my turn to testify?

The LM324 sucks. It is the filthiest, disease-riddled piece of silicon ever to insult common sand with it's presence. I once was lured into putting one on an opto. Just an ordinary opto.

"Say Duff, there's no problem if we increase the switch matrix read speed from 'adequate' to 'ludicrous speed', is there?"
"Heck no."
"Say Duff, we can read all the switch matrix except your stupid ugly pee-pee doo-doo optos."

You are joking, right?

If you do not know what is the right tool for the job, or how to use the tool that you have, just go commit yourself to being a bagger at a food mart.

The only reason that the LM324 outlived it's contemporaries is that it is sufficient for most things if you know it's limitations, and it is really CHEAP. At $0.10 each or about $0.03 per amp in reels it often is the best solution to applications that are not demanding.

The characteristics most have trouble with are the input range:

they say it will work at ground but you should really not expect it to, most actually need about 10mV before they will function properly and do not expect it to work when you get closer than 1.5V to the high rail.

and the output range: do not expect to get closer than 1.5V to the high rail with a 2K load.

Dan

 

[Oblong]

The only reason that the LM324 outlived it's contemporaries is that it is sufficient for most things if you know it's limitations, and it is really CHEAP. At $0.10 each or about $0.03 per amp in reels it often is the best solution to applications that are not demanding

Agreed only an idiot uses a 3 to 6 dollar op-amp when a 5 to 40 cent one will do the job.

I'll be more specific I still use the 358,358a and 258a and 324 as long as they do the job why wouldnt you.They are cheap and widely available. I don't use these exclusively but I will select the cheapest amp that does the job. Depending on the application it may be a 3 to 6 dollar one or a cheapo 358 324 or somewhere in between.

Not every application requires high BW and precision (low offset) and low distortion, noise etc.

 

[Kranthikkenoch]

Hello everyone....

You already have a thread on this topic, do not multi-post!

Moderator.