Dual source for opamp ?

[Nhan95]

When we use opamp LM741 or others, we need to supply a dual source. Could you tell me how to create a dual source from single one. Ex. from 9V we create dual source (+9V)_(-9V) . thanks 

[electr_peter]

When we use opamp LM741 or others, we need to supply a dual source.

No, you don't need dual voltage supply. Single supply is enough if signals can be shifted to ~half rail.

Could you tell me how to create a dual source from single one. Ex. from 9V we create dual source (+9V)_(-9V) . thanks 

9V DC can be split into 4.5V and -4.5V with resistor divider and op-amp in follower configuration. To get +/-9V you need to either increase voltage 2 times or create negative 9V voltage with DC/DC converter.

[Richard Crowley]

As electr_peter said, it is not necessary to use dual/split power voltages for an op-amp.  There are many circuits that operate on a single supply and use methods such as creating a "virtual ground" of VCC/2, etc.

There are also circuits (and commercial modules) that take some positive voltage and generate an equivalent negative voltage. Some of these are quite inexpensive and available on ebay, etc.

Since you did not disclose anything about your proposed application/circuit, we are unable to recommend any particular solution.

[jlmoon]

If this is a new design, I hope you're forward looking in selection of your op-amp part.  I believe the 741 is severely outdated and would suggest something much better / newer such as the TL0xx series.  They will perform much better with single supply as well.  I have never tried using a 741 at +- 4.5 Volts either, not sure that is within the minimum supply rail specifications.

 

[Obin]

from http://tangentsoft.net/elec/vgrounds.html
i love the tle2426 If you're going to put a lot of 'load' on the ground, it's best if you put a simple buffer behind the TLE to soften the blow