I just noticed that as well; it's fixed in version 1.02 of the datasheet released in back in late March (though some of the other issues still aren't). Overall it looks like an interesting part for DC servos--my shortlist there is the TL071, LME49880, and ADA4637. The 49880 fills the gap between the TL071 and ADA4637 rather nicely, though the TL071's plenty for the standard servo implementation where all the servo does is integrate.
For servo duty, there are some newer TI offerings which look worthy. That is assuming that lowish noise and bias currents are desirable (they would be to me if I were seeking out a servo amp). OPAX141, OPAX376 and OPAX209. The latter is bipolar but has lower noise than any JFET I've seen coupled with commendably low input bias current for a bipolar. They're all considerably lower cost than the AD part you've mentioned though clearly dearer than the humble TL071.
Yeah, nice parts, particularly with the SOT-23 availability in the single channel versions. Too bad the OPAx209's a RRIO and hence likely requires it's own set of rails in typical audio designs; particularly good specs there. For 15V rails the LMC6801 might be an interesting alternative.
So far I've found the TL071's quiet and low bias enough as an integrator. What usually pushes me away from it's need for speed and linearity characteristics more like an audio op amp. Haven't found a precision op amp with both those properties, though I haven't looked particularly hard.
So far I've found the TL071's quiet and low bias enough as an integrator. What usually pushes me away from it's need for speed and linearity characteristics more like an audio op amp. Haven't found a precision op amp with both those properties, though I haven't looked particularly hard.
The OPAx376 is CMOS, limited to 5.5V supply. The thing to watch with these low noise CMOS amps with rail-rail inputs is that the full CM input voltage range isn't usable for audio (i.e. with low distortion) so they ain't really RRI. This TI part is better than most, it can go to about 1V below the positive rail before distorting. One of Maxim's similar parts (MAX4475) doesn't do half as well though its noise is even better. The headline low distortion figures (which, let's face it, are pretty impressive) are only achieved when keeping within this CM input voltage limit.
lme49990 = winner by a mile and ad797 has been my favorite chip for years. i'm yet to try it out in any regulator designs, 797 was also incredibly versatile; but i surely will. so far i have used it in simple iv and in opc's 'the wire' headphone amp with balanced input and lme49610 in the se output. this combo is killer, best sound i have ever heard from chips and owens name for his amp is entirely apt
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LME49990MA
I have seen these for sale on element14.com
I have implemented these on a WM8741 mono dac as a summing buffer and it was very suited in this application.
Sound wise was very extended BASS! Clear mid range with a sweet top end.
I have tried a few op amps like the famous AD825, and the LME49990 was more smoother with a more solid low end.
Cheers,
Rod.
I have seen these for sale on element14.com
I have implemented these on a WM8741 mono dac as a summing buffer and it was very suited in this application.
Sound wise was very extended BASS! Clear mid range with a sweet top end.
I have tried a few op amps like the famous AD825, and the LME49990 was more smoother with a more solid low end.
Cheers,
Rod.
THank you for this advices.I have seen these for sale on element14.com
I have implemented these on a WM8741 mono dac as a summing buffer and it was very suited in this application.
Sound wise was very extended BASS! Clear mid range with a sweet top end.
I have tried a few op amps like the famous AD825, and the LME49990 was more smoother with a more solid low end.
Cheers,
Rod.
LME49990MA
Is the AD797 better than the LME4990?
Well I have no AD797 to try the A/B Test.
A look at both data sheets suggest a close match as specs are concerned.
When you compare a high spec op-amps is that the power supply and the quality of surrounding components plus the particular application will influence the sound quality.
The best way is to compare the op-amps in your application.
Ensure that you use top quality components and power supply rails.
Cheers.
Is the AD797 better than the LME4990?
Well I have no AD797 to try the A/B Test.
A look at both data sheets suggest a close match as specs are concerned.
When you compare a high spec op-amps is that the power supply and the quality of surrounding components plus the particular application will influence the sound quality.
The best way is to compare the op-amps in your application.
Ensure that you use top quality components and power supply rails.
Cheers.
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