What opamps do you have in your drawer besides LM324... - Page 1
Forum section: electronics / projects

author: Martinn
author_rank: Frequent Contributor
timestamp: August 27, 2023, 09:45:54 am
content: ... 741, NE5532, TL082, OP07?Since JLCPCB assembly got mindblowingly cheap, fast and easy my PCBA just for fun output exploded. So easy to try out stuff... Still for working out details quickly, breadboarding is much faster provided you have the parts on hand. I prefer Jim Williams style on copper clad PCBs, I don't like solderless or perfboards much because of the missing GND plane, but still need to stock up my opamp selection. Of course this depends a lot on the area you work on, like precision, speed, low power, audio... and for that reason the title is not "What are the best opams for prototyping".Also I exclude jellybeans here (BTW JLCPCBs jellybean shortlist is herehttps://jlcpcb.com/parts/basic_parts(select opamp category)). BTW2 JLCPCB charges $3 for every non-basic component type, so if you place an opamp from the still thin, but rapidly growing LCSC stock, the setup cost often is higher than the component cost. This also is a reason to have non-jelly stuff at hand - just order the PCBA with the basic stuff like all the annoying 0402 decoupling capacitors and add remaining components manually. Unfortunately wetting on the already reflow soldered PCBAs is mediocre.Similar questions already asked a couple of years agohttps://www.eevblog.com/forum/projects/what-is-your-favorite-most-versatile-op-amp/https://www.eevblog.com/forum/chat/favorite-op-amp/https://www.eevblog.com/forum/metrology/please-suggest-me-a-selection-of-operational-amplifiers-for-dc-experimentation/https://www.eevblog.com/forum/projects/good-modern-op-amps-and-comparators-for-stock/so feel free to ignore this topic if you consider it redundant.Since many modern opamps are available in SOT23-5, I wonder if I should make a tiny breakout board that contains supply decoupling and feedback resistor. Otherwise something like the ADA4895 (this one is in my drawer, 1 nV/rtHz decomp. 10x gain 230 MHz) just gets an oscillator.Analog has something a bit biggerhttps://www.analog.com/media/en/technical-documentation/user-guides/EVAL-HSOPAMP-1RJZ_UG-838.pdfProbably better:https://www.ti.com/tool/DIYAMP-EVMMaybe this together with an SOT-23 assortment would be a great basis. Analog has 123 types in that case:https://www.analog.com/en/parametricsearch/11070#/ps5=5-Lead%20SOT-23|5-Lead%20TSOT|5-Lead%20TSOT-23|6-Lead%20SOT-23|6-Lead%20TSOT-23|5-SOT_23-N/A&sort=s3,ascThanks, Martin

author: coppercone2
author_rank: Super Contributor
timestamp: August 27, 2023, 10:03:57 am
content: LM324J is a good chip besides LM324

author: Kleinstein
author_rank: Super Contributor
timestamp: August 27, 2023, 11:07:04 am
content: There is no real need to make your own breakout bords. There are ready made SOT23-6 to 6 pin dip like adapter boards and the decoupling capacitor can be bodged on (solder one side and an air wire for the other side).For really high speed parts one may have to order a PCB anyway.The OP-amps in the drawer are to a large part left overs from old projects when you order 1-2 spares or just the worng case (e.g. wide SO8) by mistake.In the old days with mainly DIP this was easier - now it is also about the right case: a SO8 version no good if you need SOT23-5 with also possibly different pin-outs.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 27, 2023, 02:00:27 pm
content: TI used to have free PCB breakout bords for the most common opamp footprints of their ICs, with PCD pads to solder decoupling SMD caps and feedback resistors. They were heaving names likeDEM-OPA-SO-1A, DEM-OPA-SO-2B, DEM-VCA-SO-1B, DEM-BUF-SOT-1A, etc.When I ordered them from the TI Store (Texas Instruments official store, I used to buy TI devboards from there), the PCB breakout boards were free in quantities of maxim 5. No idea if TI Store still exists.

author: Martinn
author_rank: Frequent Contributor
timestamp: August 27, 2023, 02:53:08 pm
content: In one of the threads I referred in my initial post the OPA192 was recommended. I took the TI parametric search and narrowed it down some:https://www.ti.com/amplifier-circuit/op-amps/products.html#78=In%3BIn%20to%20V%2B%3BIn%20to%20V-%3BIn-Out%3BOut%3BBlanks&480=1&1261max=10%3B180&23typ=5%3B8000&2max=0.002%3B0.1&sort=1130;asc&givingOPA197OPA182OPA189OPA192OPA210OPA211What about super beta (OPA210)? David Hess commented on thosehttps://www.eevblog.com/forum/projects/what-is-your-favorite-most-versatile-op-amp/msg2393631/#msg2393631Application note:https://www.ti.com/lit/an/sboa305/sboa305.pdf?ts=1693147633722mentions the much lower input current noise.Should one have those on the radar?

author: wraper
author_rank: Unknown
timestamp: August 27, 2023, 03:11:33 pm
content: Quote from: coppercone2 on August 27, 2023, 10:03:57 amCeramic package does not make it a different chip, just makes it very expensive version of otherwise cheap op-amp with poor specs.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 27, 2023, 04:45:47 pm
content: Some SOT-23(5) and SOT-23(6) OPAs which I happen to have at hand:AD8628ADA4051ADA4084LT1800LT1806OPA189OPA341THS4281EL5104ISL28191ISL28134LMP7731

author: Kleinstein
author_rank: Super Contributor
timestamp: August 27, 2023, 05:08:52 pm
content: Quote from: Martinn on August 27, 2023, 02:53:08 pmThe OPA210 and OPA211 are low voltage noise, but come with high supply current and current noise. So a bit more special types.The more practical of the OPA2xx series is the OPA202: it is my OP07 replacement with lower power and less 1/f and current noise.

author: Infraviolet
author_rank: Super Contributor
timestamp: August 27, 2023, 05:37:58 pm
content: I tend to favour the MCP6024 or MCP6294 (both virtually the same, usually swappable for one- another) for general prototying. 6V/us slew rate and easy to run as rail-to-rail with only a 5V and ground rail. Regreattably the 6024 is only made by a single company, Microchip, so not so pleasant during the chip crisis, but I think the 6294 is also made by others, TI for some reason has a datasheet available for it.The good thing about quad op amps is most of them have the same physical pinout too.

author: Martinn
author_rank: Frequent Contributor
timestamp: August 27, 2023, 05:40:57 pm
content: Quickly going through the datasheets...Quote from: Neomys Sapiens on August 27, 2023, 04:45:47 pmThanks!

author: floobydust
author_rank: Super Contributor
timestamp: August 27, 2023, 06:06:01 pm
content: To reiterate - it's the quality of the op-amps in the drawers that matters. Cheap junk semi's save you no money when you factor in time figuring out why it doesn't work as expected.I got some cheap parts and slow as molasses despite using the popular part number. Unisonic TW datasheets even out to lunch for some of their parts what a waste of time.

author: Martinn
author_rank: Frequent Contributor
timestamp: August 27, 2023, 06:46:54 pm
content: Quote from: floobydust on August 27, 2023, 06:06:01 pmProbably depends on what kind of work you do. If you design electric toothbrush wireless chargers, you'll probably fight for microcents given the absurd volume and your junk can't be cheap enough.Few people probably are into this business though. For the rest you are correct. Maybe feels a bit strange if you use a $10 precision opamp as VCC/2 generator (where a LM358 would have been fine as well).Probably also a thing to be aware of are those countless Chinese manufacturers like Gainsil (many more on LCSC) - but as long as I can afford Analog Devices or TI, I'll use those. For my personal fun stuff cost is not really an issue anyway.

author: Kleinstein
author_rank: Super Contributor
timestamp: August 27, 2023, 06:53:42 pm
content: For prototyping too fast an OP-amp can also be a problem, as the fast ones may work as an oscillator instead of amplifier.More than some 10 MHz GBW often needs care with the decoupling and capacitive loading.There is no one size fits all, but a few different types that make sense to have available. The more special types usually come in as spares from prior use.For prototypes the price is less important, but using yellybean parts can save on the time needed to look up data-sheets.

author: coppercone2
author_rank: Super Contributor
timestamp: August 27, 2023, 07:51:56 pm
content: Quote from: floobydust on August 27, 2023, 06:06:01 pmhence theJsome of those parts are so bad you think the comparators have a bimetalic strip

author: wraper
author_rank: Unknown
timestamp: August 27, 2023, 08:09:30 pm
content: Quote from: coppercone2 on August 27, 2023, 07:51:56 pmLOL, why would you buy the worst variant of a x24 in military version? It's the the same cheap op-amp with exactly the same die but with more rigorous testing, expensive package and only 0-70oC operational temperature range. Get a regular LM224 or LM124 instead if you need wider temperature range. Not to say it's basically the cheapest op-amp available which is good enough for many applications. You use it not because it's good but because its cheap and good enough for non demanding use. As of how op-amp operates, military variant is not better in any way. The best idea ever to take $15 (but poor performance) op-amp from the drawer and fear blowing it up on the breadboard because something was not wired correctly.

author: David Hess
author_rank: Super Contributor
timestamp: August 28, 2023, 02:53:01 am
content: I am only including parts that I might restock, even with an alternative, which are in my parts drawers now:uA741 - I would like to find an inexpensive improved replacement, but apparently there is not one unless you want to spend 10 times more. Unfortunately the LM301A is being discontinued.LM308 - Legacy low input bias current bipolar.LM318 - Fast bipolar - still produced.LF351/LF353/LF347 - National equivalent to TL071 series.TL071/TL072/TL074 - JFET single/dual/quadOP07 - PrecisionOP90 - Micropower single supply precision - like an LT1077 or slow single precision 324.LF356 - Fast JFETLF357 - Faster Decompensated JFET324/358 - I do not like these, but I still have some.LM833 - AudioI am adding the OPA1641 to my collection as a single supply, low input bias current, low noise, low drift, 36 volt part. The lower offset and drift OPA140 is much more expensive and the OPA145 is unavailable.

author: GelatinCapacitor
author_rank: Contributor
timestamp: August 28, 2023, 05:47:27 am
content: I'm an audio type of person.Pretty much every OPAMP I've got I've got them from scraps; so, I have lots of 4558s.Every OPAMP I've bought are NE5532, and have only bought very few.

author: coppercone2
author_rank: Super Contributor
timestamp: August 28, 2023, 07:13:52 am
content: Quote from: wraper on August 27, 2023, 08:09:30 pmhave you tried one?

author: moffy
author_rank: Super Contributor
timestamp: August 28, 2023, 08:32:42 am
content: Quote from: coppercone2 on August 28, 2023, 07:13:52 amWraper is correct, MIL spec parts come off exactly the same production line as all the other parts just with expensive and rigorous testing. Bob Pease wrote an article that since the National Semi chip failure rates for many devices were in the few PPM that MIL testing was an unnecessary expense as their commercial parts had the same reliability as the MIL spec'd. In the late 80's and 90's militaries in the West realised they were paying too much and switched to largely commercial parts. MIL spec parts then largely disappeared from manufacturers and the once ubiquitous ceramic package became a novelty. Having worked in military avionics in the 80's we sure had our fair share of parts failures. Also for National Semi an LM124 used to mean military, LM224 industrial and LM324 was commercial but all the die came from the same production line.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 28, 2023, 09:06:08 am
content: LM741 has a supply voltage of up to 44V, and that can be a plus in some situations. For example a common and cheap chinese power supply kit, which is a copy of a magazine article from the '80-ies replaced it with a tl071 which is rated for a more common 36V, and that is a bit low for a rectified 24V transformer. There are more modern opamps that go up to 44 too, but nowaday's the trend is more towards low power stuff, such as maximum of 6V.I there any price difference between TL072 and TL082? Those opamps are nearly identical, only TL072 has lower noise (Officially that is). These day's they are probably just the same, but maybe there is still some sorting in the factory?"Power Opamps" tend to be weirdly expensive, but you can also use audio amplifiers such as TDA2050, TDA7293 and LM3886. TDA2050 is now also being obsoleted though. With such an audio amplifier it's quite easy to make an adjustable power supply or a power DAC.

author: wraper
author_rank: Unknown
timestamp: August 28, 2023, 10:24:46 am
content: Quote from: coppercone2 on August 28, 2023, 07:13:52 amWhat I have to see other than it operating exactly the same as regular LM324 in plastic package? I don't have LM324J but I have other chips including op-amps in military variants and they work exactly the same as normal versions. If you believe LM324J somehow operates better than normal version, compare specs in the datasheets.

author: Kleinstein
author_rank: Super Contributor
timestamp: August 28, 2023, 11:36:25 am
content: I have used LM139 in a ceramic case. Not because they were better (they still have a larger specified temp range) than the more normal LM339, but because I got them in mixed bag. Except for maybe the larger temperature range there is little need for the MIL spec parts - for the higher temperature we now have automotive spec parts.

author: David Hess
author_rank: Super Contributor
timestamp: August 28, 2023, 05:54:32 pm
content: Quote from: Doctorandus_P on August 28, 2023, 09:06:08 amThe 741 also has a wide differential input voltage range.QuoteThe TL071 and TL081 series are identical except that the TL071 series goes through an additional low frequency noise test, probably 10 Hz. A spot noise measurement at 10 Hz correlates well with low frequency noise and is much faster than a true low frequency noise test.Noise is process related so I suspect at some point all of the parts passed the noise test so grading the TL071 no longer made sense.

author: coppercone2
author_rank: Super Contributor
timestamp: August 28, 2023, 06:03:13 pm
content: don't forget the LM741H

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 28, 2023, 06:07:16 pm
content: I'm fond of TLV2372 over LM358. Much better, no dead zone / class C output, comparable speed and accuracy, symmetrical RRIO.OPA170, 171 for similar but more precision (and, single supply input I think it was?).Bonus mention: MCP6561 comparator. Fast, low power, low voltage.Variety of things I've used for other projects but I don't have them literally in the drawer, so, for another thread perhaps.Tim