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I want to power two opamp rails with +-12V. For that I want to use this component to obtain +/-12V split supply from a 24V single supply.

But I came across the following statement:

TLE2426 splits the opamp rails and references signal ground but not output ground.

What does that mean? Can I use use TLE2426 to power rail-to-rail opamp rails?

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That device is a virtual ground maker. That is, it creates a reference point half way between the rails. You would supply your op-amps with 24V and Ground and use the output of this device as your signal/analog ground.

Something like this.

schematic

simulate this circuit – Schematic created using CircuitLab

Note internals of the rail-splitter is simply a voltage divider and a unity gain op-amp buffer.

enter image description here

As such it can't source or sink more than 20mA so do not use it for higher currents.

Addition: Note the circuit can be equally labelled as follows.

schematic

simulate this circuit

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  • \$\begingroup\$ Is there any benefit over using this rather than an op amp (other than, maybe, fewer components) for the virtual ground? I've often used two equal resistors creating half +V into the positive of the op amp and just set it up as a voltage follower. \$\endgroup\$ – DiBosco Sep 26 '17 at 15:48
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    \$\begingroup\$ @DiBosco Looking at the spec sheet that's basically all it is anyway, a divider and an op-amp. Benefit is the simple 3 pin package I guess. \$\endgroup\$ – Trevor_G Sep 26 '17 at 15:51
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    \$\begingroup\$ @doncarlos depends how much current the op-amp circuits take. \$\endgroup\$ – Trevor_G Sep 26 '17 at 16:53
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    \$\begingroup\$ @doncarlos If you need a lot more current then you are better off creating proper +-12V rails in the first place. \$\endgroup\$ – Trevor_G Sep 26 '17 at 16:55
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    \$\begingroup\$ @doncarlos you need to stop confusing signals with power. The ecircuit you show produces two reference signals, and is not a power supply. You also have to power those op-amps with some rail beyond those voltages. I can't tell you what to stick with since it depends on the whole circuit, not just this part. But usually the LTC device is meant for a quick circuit. It's not intended to be the reference for say a whole stereo system. \$\endgroup\$ – Trevor_G Sep 26 '17 at 17:09
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TLE2426 splits the opamp rails and references signal ground but not output ground.

The source/sink capability of the TLE2426 is only \$ \pm 20 \$ mA. So, you would not reference any sizable output load to this virtual ground.

For example, if you were driving a speaker, you would tie one terminal of the speaker to your negative supply and AC couple from the output of your opamp to the other terminal of the speaker.

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