Hi
I'm in the need of a plus minus (+/-) supply voltage for an opamp. The opamp is used in an input buffer for a ADC used for a microphone.
I'm dealing with a battery supplied application so the trouble is how I produce a negative voltage and a positive counterpart.

I have:
+12 V supplied by a battery

I need:
+-3.2 V for an opamp

I'm wondering if I can use the LT3032 from Linear Technology.
And then before that produce a pseudo ground with a voltage divider (using resistors) and then an opamp. Illustrated here in Figure 7.

Can anyone help me understanding this better?
Or are there other suggestions?

 

Hello,

The schematic you point at is rather confusing.
There are ground signs al over.
I have put text where the virtual + and - will be.

I also attached a PDF with all kinds of single supply opamp circuits.

Bertus

 

So you suggest that the opamp configuration producing a virtual + and virtual - along with ground will supply my LT3032?

I am also confused with the many ground signals. The signals marked with * will be a separate ground, right?

Can someone make an outline for me. For the entire circuit I need +5V, +3.2V and -3.2 V.... My only supply is a +12 V battery.
My thoughts are using a configuration like shown in the thread above. And then use some linear regulators to produce my exact voltages of +5 V, +3.2 V and -3.2 V...
Does that sound ok?

 

Hello,

When you feed the opamp with 12 Volts , you will get + and - 6 Volts virtualy.

Bertus

 

Have you seen this?

Bill's Index

Creating a Virtual Power Supply Ground