CMOS equivalent of LM324 - Page 1
Forum section: electronics / projects

author: garvind25
author_rank: Regular Contributor
timestamp: May 16, 2025, 08:53:33 pm
content: Hi,Can anyone suggest a CMOS equivalent of LM324 pls? I need 4 op amps in a DIP package for my project.Thanks in advance,Arvind Gupta.

author: Zero999
author_rank: Super Contributor
timestamp: May 16, 2025, 09:57:05 pm
content: There isn't one really.What do you mean by equivalent?The LM324 can withstand input voltages up to 32V, irrespective of the actual supply voltage, but no CMOS op-amp can do that.

author: temperance
author_rank: Super Contributor
timestamp: May 17, 2025, 01:02:43 am
content: Do you need a CMOS op amp Because of input bias current? Supply current? If you want people to suggest you something useful you must provide enough information. In the case of CMOS op amps the required maximum supply voltage is important. CMOS op amps capable of working with supply rails as high as 36 V do exist for some premium price. The majority of CMOS op amps are made to work with 5.5 V max. and some like the TLC272 series can work with supply rails op to 16 V.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 17, 2025, 01:32:01 am
content: Quote from: garvind25 on May 16, 2025, 08:53:33 pmAs above, there are no 100% CMOS equivalents, and these days DIP is a rare package, for new products especially.A common low voltage alternative is the LMV324 etcThere are a JFET input LF347, TLE2064 etc that is old enough to be in DIP, but that has a different common mode range.Addit: I see a recent TI release as this TLV9304• Low offset voltage: ±0.5 mV (typ)• Low offset voltage drift: ±2 µV/°C• Low noise: 33 nV/√Hz at 1 kHz• High common-mode rejection: 110 dB• Low bias current: ±10 pA• Rail-to-rail output• Wide bandwidth: 1-MHz GBW• High slew rate: 3 V/µs• Low quiescent current: 150 µA per amplifier• Wide supply: ±2.25 V to ±20 V,4.5 V to 40 V• Robust EMI performance: 72 dB at 1 GHz• MUX-friendly/comparator inputs: – Differential and common-mode input voltage range to supply rail• Industry-standard packages: – Quad in SOIC-14 and TSSOP-14Notice because it is new, they do not offer DIP14.

author: jwet
author_rank: Frequent Contributor
timestamp: May 17, 2025, 02:17:09 am
content: The TI TLC274 series including the 27M4, etc are the closest thing that I know of as an equivalent. Their max total supply is 16v. Their common mode goes to ground, they have similar GBW, Similar Offset, etc. and could be plugged in with few surprises. They have a CMOS input with 10^12 ohm inputs. Cheap.Some of the others like the LF347 are JFET with terrible offset (5 mV), draw about 10x the power and have a CMVR about 4V from the PS rails. They do take wide supplies.(44v).The LMV324 are lower supply voltage parts (6V max) and have miserable CMVR and CMRR. They're also slower. These parts shouldn't exist.

author: xavier60
author_rank: Super Contributor
timestamp: May 17, 2025, 08:19:18 am
content: There is a quad version of my go-to opamp, not cheap.https://www.digikey.com.au/en/products/detail/texas-instruments/TLC074CN/378330

author: Kleinstein
author_rank: Super Contributor
timestamp: May 17, 2025, 09:04:54 am
content: Cheap CMOS for >=32 V supply are TL074H. It is a new and cheap part, but not available in DIP.The TL07xH are also no single supply, but work up to the upper supply level.It is very similar to the old JFET type TL07x but is actually CMOS.The TLV9304 is close to the LM324, but also not available in DIP.Many other CMOS chips (e.g. OPA170 / TLV170) have diodes to limit the differential input voltage.There is the old CA3240 that is a dual that is available in DIP. It was a kind of old standard part, but got rather expensive by now.

author: David Hess
author_rank: Super Contributor
timestamp: May 17, 2025, 12:34:57 pm
content: Older Texas Instruments CMOS DIP parts, like the LMC6081, are limited to 16 volts. Newer 40 volt CMOS parts like the OPA170 use SOIC packages and have a limited differential input voltage range.As an alternative, Texas Instruments has high voltage single supply JFET parts like the OPA4141, but again, they use SOIC packages. They are also much faster than a 358/324.

author: mawyatt
author_rank: Super Contributor
timestamp: May 17, 2025, 01:11:26 pm
content: Why not get whatever CMOS op-amp is available that meets the OP electrical requirements/needs and use an adapter PCB for the DIP requirement/need? We've done this many times for various ICs that weren't available in DIP packages, or we didn't have any around to grab.Best

author: temperance
author_rank: Super Contributor
timestamp: May 17, 2025, 01:45:39 pm
content: The TL074H input is not compatible with the LM324.LM324: input common mode range includes GND or the neg. supply rail but not VCC.TL074H: input common mode range includes VCC but not GND. (You can see that immediately from the input structure as shown on the TI website.)

author: xavier60
author_rank: Super Contributor
timestamp: May 17, 2025, 01:59:39 pm
content: To avoid possible misunderstanding, The TLC074CN's common mode range does include ground.Edit: data sheet indicates common mode range including ground is conditional on supply voltage, 12V. In practice, I have no problem at 8V.

author: Zero999
author_rank: Super Contributor
timestamp: May 17, 2025, 03:31:39 pm
content: Quote from: garvind25 on May 16, 2025, 08:53:33 pmWhy can't you use the LM324? What project? Post a schematic?

author: garvind25
author_rank: Regular Contributor
timestamp: May 21, 2025, 04:03:43 pm
content: Thanks for your comments. As I understood, its difficult to find a LM324 CMOS equivalent. Also there seems to be some difficulty in my existing project. So I have decided to start fresh.Can anyone pls suggest a simple low cost, general purpose CMOS op amp to try out simulations with? It needs to be available in the LTSpice library so that I have the accurate model to work with.Thanks again for all your efforts.Arvind Gupta.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 21, 2025, 06:04:25 pm
content: Most OP-amp circuits are designed in a way that they don't depend on the details of the OP-amp. The beauty is that one can often exchange types if needed for parameters like costs, noise, speed or power consumption.So one usually designs in a way that the exact model does not matter.Rather common, cheap CMOS OP-amps are TLC272 , TL072H and MCP6002. They differ in the supply range, speed and common mode range however.

author: garvind25
author_rank: Regular Contributor
timestamp: May 24, 2025, 03:53:02 am
content: Quote from: Kleinstein on May 21, 2025, 06:04:25 pmThanks for the list. Can you pls confirm if any of these op amps can be used for dual power supply (such as +2.5v and -2.5v or +5v and -5v and so on). I guess it will be good to select an IC which has all the necessary features in the beginning itself rather than having to change the IC in every project.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 24, 2025, 04:07:47 am
content: LM324 is a very old opamp, but it's good enough for many specifications, and it's very cheap because it's made in huge numbers.Your question does not make much sense to me. Why do you want specifications to "be the same" (while at the same time having "CMOS", so a different design.There are thousands of opamps, and all have their specific flaws. Pinouts of opamps are mostly compatible with each other, so you can buy a bunch of different opamps with different mix of properties and flaws.To me it looks like you don't know much about opamps (yet) and want an easy start. Having a bunch of different opamps is good for beginners. It allows you to examine their differences, and how their different properties influence the circuit you are building. Prices of these things (even from western shops) start at around 20ct, so even buying a handful of different versions is still quite affordable for most people.

author: ledtester
author_rank: Super Contributor
timestamp: May 24, 2025, 04:12:12 am
content: Quote from: garvind25 on May 24, 2025, 03:53:02 amThe TLC272 datasheet reports its min/max supply voltage as 3V/16V and its schematic shows a "GND" connection but it can be used with a +/- supply.Indeed, all op-amps can be used with +/- supplies or GND-based supplies.All that matters is the difference between Vsupply+ and Vsupply-. There is a minimum and maximum for this difference.For the TLC272 this range is 3V to 16V.For the TL07x it's 4.5V min and 40V max.For the MCP6001 the min is 1.8V and the max is 6V.Note that the supply voltages don't even have to be symmetric -- you could have Vsupply- be -2V and Vsupply+ be 5V. The difference is 7V which make it usable with the TLC272 and TL07x but not the MCP6001.Datasheet links:-https://www.ti.com/lit/ds/symlink/tlc272.pdf-https://www.ti.com/lit/ds/symlink/tl072.pdf-https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf

author: David Hess
author_rank: Super Contributor
timestamp: May 24, 2025, 05:00:28 am
content: Quote from: Doctorandus_P on May 24, 2025, 04:07:47 amThe LM324/LM358 is cheap because it was optimized to have a small die size by using transconductance reduction to allow the use of a much smaller integrated compensation capacitor. The 741 has a 30 picofarad compensation capacitor which takes up most of the die, while the 324/358 has a 5 picofarad compensation capacitor. This is also why there were never comparable dual and quad 741 parts; the dual or quad die was too big for even DIP packages.There are dual and quad operational amplifiers with "741 performance", but they use a different topology. I did a survey once to try and find a 741 design which uses transconductance reduction, but I was never able to confirm one. For instance some schematics for the 1458 show transconductance reduction, but not the compensation capacitance, while others show 30 picofarads of compensation, but no transconductance reduction, so I do not know what to think. More commonly dual and quad operational amplifier with "741 performance", like the 4558 or 4136, have PNP input stages and are faster.

author: eblc1388
author_rank: Frequent Contributor
timestamp: May 24, 2025, 06:14:23 am
content: Quote from: David Hess on May 24, 2025, 05:00:28 amI did remember seeing a ua747 by Fairchild years ago. It is a dual 741 in a 14-pin dip or 10-pin metal can package. The datasheet shows it has 30pF compensation capacitor and using NPN input stages.https://datasheet4u.com/pdf-down/U/A/7/UA747-Fairchild.pdf

author: tooki
author_rank: Super Contributor
timestamp: May 24, 2025, 08:59:54 am
content: Quote from: garvind25 on May 21, 2025, 04:03:43 pmI don’t think you did understand.It’s difficult whenyourefuse to provide any of the information that was requested of you. You literally have not answered one single question.Nobody should bother responding in this thread until YOU answer all the questions that have been asked. People asked them for a reason.

author: David Hess
author_rank: Super Contributor
timestamp: May 24, 2025, 09:46:45 am
content: Quote from: eblc1388 on May 24, 2025, 06:14:23 amSure, but that is a dual in a larger 14 pin DIP package rather than the 8 pin. There are a bunch of examples where the dual part was too large for the 8 pin DIP package, which became even more of a problem with SOIC parts.

author: garvind25
author_rank: Regular Contributor
timestamp: May 24, 2025, 06:26:07 pm
content: Quote from: Kleinstein on May 21, 2025, 06:04:25 pmUnfortunately these ICs are not there in the LTSpice library. I had thought that you had answered my post accordingly and thus I didnt check the LTSpice library previously. When I sat down to restart working I cant find these components in the LTSpice. So now I am back to square one. Requesting you to pls suggest any cmos op map in the LTSpice library which are common and easily available.

author: Zero999
author_rank: Super Contributor
timestamp: May 24, 2025, 08:29:44 pm
content: Quote from: garvind25 on May 24, 2025, 06:26:07 pmIt was a silly question. Why limit yourself? Just download the appropriate model and paste it into the .asc file. Here's an example.https://www.eevblog.com/forum/beginners/op-amp-negative-feedback-gain/msg3202682/#msg3202682

author: David Hess
author_rank: Super Contributor
timestamp: May 24, 2025, 11:12:04 pm
content: There are bipolar equivalents to the LM324 with closer to CMOS performance.The LT1079 is an improved LM324 with 200 microamp supply current and 6 nanoamp input bias current. The LT1179 is an improved LM324 with 68 microamp supply current and 3 nanoamp input bias current.

author: tooki
author_rank: Super Contributor
timestamp: May 25, 2025, 10:19:41 am
content: Quote from: garvind25 on May 24, 2025, 06:26:07 pmSince you refuse to answer any questions, why don’t you also just look for yourself? You have LTSpice installed, so click through its op amps and see which ones look promising, then go on your preferred distributor and see what the availability is like.