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I would like to supply +4.5V & -4.5V to OpAmp using a 9V battery. I have tried using voltage divider which works. Please suggest if this is the best practice, are there any better ways of doing this.

Note: Output current required is below 100mA.

Pravi
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  • Check the [Triadtron on this page](http://www.tubecad.com/2010/07/blog0189.htm) it should be able to source/sink about 20mA on the middle rail. – jippie Nov 22 '14 at 13:48
  • Whoops I meant the chapter called "Triadtron rail splitter". – jippie Nov 22 '14 at 16:36
  • @ Cornelius, Camil Staps, Ricardo, placeholder, and Leon Heller: The previous question you referred to referred to generating a low-current negative supply from an existing power supply, expressly for the negative rail of an XR2206, which is quite different from splitting a supply for a fairly high current output in the way user44776 requested. Moreover, there was no mention of using switchers in the previous answers, so user 44776s's question elicited answers which are unique, making his question valid. – EM Fields Nov 22 '14 at 18:03

2 Answers2

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You can put an opamp buffer after your voltage divider for more current.
TI makes a rail splitter, but I've never used it.

George Herold
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"Best" is a judgement call and will depend on your application. However, since you've stated that the output current required (ostensibly from the supplies) is in the vicinity of 100 mA, using a voltage divider will result in a lot of needless waste and meandering about the pseudo-ground.

If you want a stable ground and maximum life from your 9 volt battery, I suggest you use a couple of buck-boost regulators to get the + and - 4.5 volts you need. Here are a few offerings from LTC, and Here are a few from TI

EM Fields
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