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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Sun Aug 19, 2018 12:52 pm Post subject:
TL071 TL072 opamp substitutes - high quality low current |
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I haven't found any discussion here of choosing opamps.
There's loads elsewhere on that but after reading around quite a bit I'm left with a simple question:
Is there a fet input opamp that will substitute for TL071 or TL072 with higher quality but also similar power requirements?
I have used OPA2134 and others with good results depending on the circuit, but the current requirements are at least double that of a TL072.
It seems to me that for situations where driving a low impedance load is not required there might / should be a modern high performance opamp that would give similar quality to a OPA(2)134 but use less power.
Does it exist? |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Sun Aug 19, 2018 11:15 pm Post subject:
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OPAx172
This opamp has no offset inputs in the single opamp version, but the offset is much lower as the TL071/072 _________________ my synth |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Mon Aug 20, 2018 5:57 am Post subject:
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interesting! thanks!
but not available in a DIY friendly DIP8 package is it?
open loop gain vs frequency is similar to the OPA2134 but power consumption is half. slew rate is slower but that probably isn't an issue.
do you have experience using these in DIY audio? |
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ixtern
Joined: Jun 25, 2018 Posts: 145 Location: Poland
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Posted: Mon Aug 20, 2018 7:54 am Post subject:
Re: TL071 TL072 opamp substitutes - high quality low current |
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halfshavedyaks wrote: | I haven't found any discussion here of choosing opamps.
There's loads elsewhere on that but after reading around quite a bit I'm left with a simple question:
Is there a fet input opamp that will substitute for TL071 or TL072 with higher quality but also similar power requirements?
Does it exist? |
LT1057A? |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Mon Aug 20, 2018 9:20 am Post subject:
Re: TL071 TL072 opamp substitutes - high quality low current |
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specs don't look quite as good as the opa172, but it is available in a DIP8.
maybe i need to learn to solder smd chips to those DIP8 adapters.
good suggestions thanks, any experience actually using either of these opamps? |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Mon Aug 20, 2018 12:13 pm Post subject:
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Didn't thought you needed diy friendly housing.
Sometimes I use chips that only are available in soic or even smaller, for that I use converters from e.g. soic to dip8 like THESE _________________ my synth |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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ixtern
Joined: Jun 25, 2018 Posts: 145 Location: Poland
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Posted: Tue Aug 21, 2018 2:57 pm Post subject:
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You cannot say OPAx172 is better than TLE207x.
They are for different purposes. TLE has better slew rate and settling time, OPA is less noisy and more precise regarding offset. |
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electrotech
Joined: Apr 24, 2013 Posts: 38 Location: Ayrshire Scotland
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Wed Aug 22, 2018 5:27 am Post subject:
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ixtern wrote: |
You cannot say OPAx172 is better than TLE207x.
They are for different purposes. TLE has better slew rate and settling time, OPA is less noisy and more precise regarding offset. |
it seemed better on the things I was looking at.
can you explain settling time and where I find it in the datasheet? |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Wed Aug 22, 2018 6:07 am Post subject:
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I tried to make a comparison table, but the datasheets do not all present the information in the same way - it makes it difficult, especially as for many specs I have limited understanding of them.
OPA2132 and OPA2172 seem like the best performance for price though overall. |
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ixtern
Joined: Jun 25, 2018 Posts: 145 Location: Poland
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Posted: Wed Aug 22, 2018 8:25 am Post subject:
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halfshavedyaks wrote: | ixtern wrote: |
You cannot say OPAx172 is better than TLE207x.
They are for different purposes. TLE has better slew rate and settling time, OPA is less noisy and more precise regarding offset. |
it seemed better on the things I was looking at.
can you explain settling time and where I find it in the datasheet? |
settling time: time to settle output voltage (as response to input voltage change) within given range (e.g. 1mV)
For OPA:
Figure 33. Large-Signal Step Response (10 V, G = –1)
Figure 34. Large-Signal Step Response (10 V, G = +1)
For TLE (e.g.):
"TLE2072M operating characteristics at specified free-air temperature, VCC± = ±15 V"
"t Settling time" |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Wed Aug 22, 2018 1:37 pm Post subject:
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I see: if I understand correctly the TLE settles to within 1mv about twice as fast.
the OPA164x seems like it is better, more like the TLE, but none of the graphs or numbers are exactly comparable. |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Wed Aug 22, 2018 11:23 pm Post subject:
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Well if you look at the distortion and noise figures (very important in audio applications) the opa164x is far superior! _________________ my synth |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Thu Aug 23, 2018 10:52 am Post subject:
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Grumble wrote: | Well if you look at the distortion and noise figures (very important in audio applications) the opa164x is far superior! |
yes of course, but we were talking about the settling time.
the OPA2172 also has excellent distortion and noise figures but less good settling, OPA1642 is good on both, but twice the price of the OPA2172.
for the price the OPA1642 is much better value than the TLE, but you have to solder it to an adapter.
there is also the OPA1652 which is a lower cost opamp, but the small signal performance looks like a lot of overshoot to me compared to the others we have been discussing.
I'm going to get some OPA1642 and some adapters, now I wonder about also getting some OPA2172 and/or OPA1652 - but I am having trouble comparing them meaningfully from the datasheets. Last edited by halfshavedyaks on Thu Aug 23, 2018 11:00 am; edited 2 times in total |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Thu Aug 23, 2018 10:55 am Post subject:
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it looks like a worthwhile improvement in input offset, but slightly higher current consumption, and other specs are not that different unless I missed something. still it is the same price as the TL072 so could be a good option for some things. |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Thu Aug 23, 2018 11:35 am Post subject:
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Quote: | we were talking about the settling time. |
I'm sorry, that was unclear to me _________________ my synth |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Fri Aug 24, 2018 12:48 pm Post subject:
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I'm going with OPA2172 and OPA1642 with adapters for now.
So I'd like to ask another question or two.
Is there a good TL07x substitue with even lower power - say less than 1ma per amp?
I have seen some good specs on some SOIC low power opamps with bipolar inputs but not fet.
and I've seen the TLE2062 and the TL032A but they are expensive for what they are and not that much better than a TL062 (except for input offset)
any other suggestions?
I have a Befaco Rampage eurorack synth module and I'm interested in improving its performance and/or lowering its power consumption, it uses 8 TL074s for a total of 32 opamps.
related to that, does anyone here use SOIC14 ICs with DIP14 adapters? If so what adapters do you use? All the affordable ones I've found so far look like they are the wrong shape for the DIP14 (ie they are square) Last edited by halfshavedyaks on Fri Aug 24, 2018 12:51 pm; edited 2 times in total |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Fri Aug 24, 2018 12:50 pm Post subject:
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Grumble wrote: |
I'm sorry, that was unclear to me |
I wasn't very clear sorry. |
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wackelpeter
Joined: May 05, 2013 Posts: 461 Location: germany
Audio files: 10
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Posted: Fri Aug 24, 2018 1:41 pm Post subject:
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LF442 and LF444 come to my mind as possible substitutes for TL072 and 74... Maybe check the datasheets if they could match your preferences…
cheers _________________ https://soundcloud.com/bastian-j |
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halfshavedyaks
Joined: Jul 12, 2018 Posts: 65 Location: UK
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Posted: Mon Aug 27, 2018 7:58 am Post subject:
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wackelpeter wrote: | LF442 and LF444 come to my mind
cheers |
hmm, interesting suggestion thanks, though I was hoping to find a better spec in a low power opamp,the LF442 has much better offset than a TL062 so worth keeping in mind.
interestingly the LF444 spec is quite a bit less good than the LF442 |
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