whats the opamp you always end up using? and why? - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: April 07, 2016, 04:09:00 pm
content: I know there's hundreds of different opamps in the market, one for each purpose or situation, but admit it, everyone has a favorite, right now, and since i started with electronics, the opamp i always end up using is the lm358, its cheap, has two inside, most of the time by inertia always use it, whats the one you always think at the first and why?

author: Audioguru
author_rank: Super Contributor
timestamp: April 07, 2016, 04:44:34 pm
content: I never use an LM358 because it is noisy, it produces crossover distortion and it has trouble with high output levels above only 2kHz. Instead I use the MC3417x single, dual and quad that have the same low power supply current per opamp, the same inputs that work all the way down to 0V and the about the same output voltage swing. But the MC opamps do not produce crossover distortion and work well with high output levels to 35kHz.Cheap? Cheep, cluck cluck. Opamps are inexpensive.

author: brabus
author_rank: Frequent Contributor
timestamp: April 07, 2016, 05:06:54 pm
content: Interesting! I also use always the same LM358, I bought a bunch of them many years ago and it's just fine.The main (only) reason why: common mode input range down to 0V.But I will try the MC3417x fr sure, thanks for the hint!

author: rolycat
author_rank: Super Contributor
timestamp: April 07, 2016, 05:56:47 pm
content: Quote from: Audioguru on April 07, 2016, 04:44:34 pmAre you sure you don't mean MC3317x?If so, they seem to be hard to come by in DIP, which may be important for beginners.

author: Delta
author_rank: Super Contributor
timestamp: April 07, 2016, 06:57:56 pm
content: LM358 for DC stuff. It can ride down to 0v on a single supply, and I have loads of them.TL074 for audio stuff. They sound fine to me, and I have loads of them.

author: rstofer
author_rank: Super Contributor
timestamp: April 07, 2016, 07:11:57 pm
content: TL081 for dual supply analog computer stuff. About to change to something else. AD4771?TLV247x for single supply. Available as 1,2 or 4 devices per packageCheck graph on page 4.5 (Figure 4.7):http://www.cypress.com/file/65366/downloadLook at the performance of the LM358See first paragraph on page 4.6

author: ciccio
author_rank: Frequent Contributor
timestamp: April 07, 2016, 07:14:57 pm
content: I'm a conservative (audio) designer.I try to use always dual units (most of the times the cost less than singles) and don't like quads because their supply pins (v+ and V-) are on the reverse sides of the chip, so:- if your PCB has straight power tracks, the quad chips is rotated 180° respect the dual : not nice to see and not liked by those who will mount the PCB.- if you want to have all chips pointing in the same direction (a board layout must be elegant) you must twist the power tracks..TL072 for unity gain circuits and tone controls, and NE5532 when low noise or high output level are needed.JRC4580 can be a good replacement for NE5532.If you need better noise or higher output drive,you can always parallel two or more amplifiers..FET inputs are better when a potentiometer is connected to OP-amp input because the lower input current make the pot less noisy.If I need a low cost quad (not on audio signal, but for secondary function, such as comparators for level indicator LEDS) I use LM324.I've tested many others, but never switched because of:a) single source andb) higher cost or problematic availabilityc) not a real improvement in performanceWhen I worked in industrial controls, the needs where different: first of all thermal stability (then OP07 was the king) and sometimes LM358.You'll have problems if you use a TL072 in a thermocouple amplifier. Guaranteed.best regards

author: Lovely_Santa
author_rank: Contributor
timestamp: April 07, 2016, 07:24:56 pm
content: Quote from: rolycat on April 07, 2016, 05:56:47 pmNowaday there are more than enough tricks to make an smd IC to a DIP package..I quick searched around:Thisis for example a solderable PCB for a SOIC8 to a DIP8...I know, maybe you don't want to solder, or want to use it multiple times for multiple IC's.. They have alsothisfor example, just the same, without soldering...

author: rolycat
author_rank: Super Contributor
timestamp: April 07, 2016, 07:39:54 pm
content: Quote from: Lovely_Santa on April 07, 2016, 07:24:56 pmI have a bunch of those. But not all beginners are confident enough to solder SOICs.QuoteThat's for a PLCC, and even then it's $22. Have you seen the price of SOIC8 adapters that don't require soldering? They are more like $250. Well out of reach of a beginner who just wants to experiment with some inexpensive op-amps.

author: forrestc
author_rank: Unknown
timestamp: April 07, 2016, 07:50:10 pm
content: Quote from: little_carlos on April 07, 2016, 04:09:00 pmTypically, I end up with a MCP6004 for my mixed signal projects:Rail to rail in and out, 1.8 to 6.0V Vcc, low iQ (100uA typ), industrial temperature range, decent enough other specs. < 50 cents qty 1, etc.. If I need a bit better Vos at the expense of iQ, I switch to a MCP6024.

author: dentaku
author_rank: Frequent Contributor
timestamp: April 07, 2016, 08:00:23 pm
content: I always end up using the LM358 for simple stuff because it swings down the bottom rail. For stuff that uses +/- power supplies I don't mind using the TL082 or 072 even though they're also ancient parts. I have no need for fancy OpAmps though.I recently got some MCP602 and MCP6004 (quad version of the MCP6002) and they're useful as replacements for the 358 in circuits that don't need more than 5V.The MCP6002/4 is nice because it's rail to rail IN AND OUT unlike the MCP602 which I think has an input range that doesn't quite reach the top rail.You can get free samples from Microchip's website too.

author: poorchava
author_rank: Super Contributor
timestamp: April 07, 2016, 08:05:53 pm
content: For general purpose stuff in single-supply world MCP6001/2/4. The same in dual supply circuits I do with TL08x. For precision applications OPA2376, OP07, MCP6V02 come to mind.Sent from my HTC One M8s using Tapatalk.

author: Zero999
author_rank: Super Contributor
timestamp: April 08, 2016, 08:02:06 pm
content: Quote from: ciccio on April 07, 2016, 07:14:57 pmWhether the TL072 is more or less noisy than the NE5532, depends on the circuit.Although the input voltage noise for the NE5532 is lower than the TL072, it has higher bias currents and a higher input noise current. If the input impedance is high (above about 25k), the NE5532 will be more noisy than the TL072.It's best to use the TL072 when a high input impedance is desired and the NE5532 for a low input impedance amplifier.http://www.ti.com/lit/ds/symlink/ne5532.pdfhttp://www.ti.com/lit/ds/symlink/tl071.pdf

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 09, 2016, 05:10:29 am
content: Quote from: ciccio on April 07, 2016, 07:14:57 pmExactly.Yours - Messtechniker