Electronic – arduino – use an op-amp to supply itself a negative voltage

arduinonegativeoperational-amplifierpower supply

For my project, I am using an LM324. According to the datasheet, its power supply can either be +/- 16V or 0-32V (max). The output will range from -3V to +3V (or there abouts), so I realise I'm going to need a positive and negative voltage supply. All I think I'll be needing is +5V and -5V to power the op-amp.

Here is the question. I'll be hooking this up to an Arduino UNO, and this can't produce said negative supply. I was thinking of using one of the 4 op-amps within the chip to invert a +5V input to give -5V. I have ran some simulations using Proteus, and according to these simulations, the idea should work, but I know from experience that theory and practice can have very different results. Would using one of the op-amps in the IC to give itself a -5V be effective, or would I have to look into an alternative method of generating -5V?

I'm using an external DC power source (not portable), and I would like to avoid batteries, if possible.

EDIT: Thanks to everyone for your answers. I had a very strong feeling that it wouldn't be possible, but something in my mind was telling me otherwise. My aim was to use as few components as possible, but I guess I was asking for too much.

I have looked at my simulations again. They are currently on a non-network PC and am unable to transfer screenshots. There was indeed a bug somewhere, and it is now telling me that what I've done is wrong, which supports all your answers.

Best Answer

You can generate a negative voltage with a small current quite simply with a source of AC, and a voltage doubler rectifier.

(This shows a doubler, reverse the diodes and capacitors for an inverter) Voltage Doubler

See here for some circuit diagrams.

The AC would come from your Arduino, by toggling a single pin regularly. You must add a series resistor too. It might be possible to use the PWM outputs, set them for 50% (AnalogWrite) and the pin will change state continuously.

Notes: as you are producing a square wave, not a pure sine wave, you will need a resistor to limit the current, as though the uC was driving a short circuit. If you only have 5 V, you should use Schottky diodes to get the most possible voltage out. Choose appropriate capacitor values for the frequency of AC that you have. Higher frequency is better, until you get to the point that the junction capacitance of the diodes becomes relevant. Available current will be small, perhaps 1/2 or 1/4 of the maximum output current of the Arduino, be careful not to overload the output pin, even during start-up when the C2 output capacitor is not charged.