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Rail-to-rail op amps?

Started by RobA, May 28, 2013, 03:14:17 PM

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RobA

I'm looking for some advice on op amps. I'm finishing up the design of an effect that needs a rail-to-rail input and output op amp to do some filtering of signal for a microcontroller. I've got a couple that work well, but I'd like to be able to suggest other possibilities as well since these two aren't available at the more guitar DIY oriented shops as far as I can find.

The two that I have that I know work are the TS922IN and TS912IN. I've tested the usually suspects, TL072, 4558, TL2272, 2082, ... and most of them fail on both rails. The LM358 and TL2272 do fine on the negative rail, but can't reach the positive rail. Anyone have any suggestions for others that will/might work?

Thanks,
Rob
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

midwayfair

LMC6482

Much lower gain than a 358 (maybe not so good for an OD), but I know it can take input below ground and it's listed as a rail-to-rail. I don't know what it's like on the positive rail. Very good fidelity. Not cheap, however.

RobA

It does look like that one would work. It's spec'd at rail-to-rail on both input and output and that seems to be the key to what works. It is a bit pricey though, especially so as it won't be carrying any audio and just control signals. But, it's worth checking out to add as an alternative. Thanks.

It looks like Small Bear does carry the TS912 and I know that it works well. Still, they want $1.50 for it and it's about 60 cents at Avnet. It would be nice to find a cheap, commonly available part for this.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).