Electronic – arduino – Negative voltage from Arduino

arduinobreadboardoperational-amplifiervoltage

I recently got a INA101HP see picture below. I was trying to use it on a breadboard. To power the op amp I connected 5V to +vcc pin but then I realized I did not really get how to provide -5V for the -vcc pin…. how is this possible if I am using an Arduino Uno as the voltage source??

enter image description here

EDIT: Based on answers received thus far

would it just be easier/CHEAPER if I got a separate 9V battery with a 9V battery cap and connect the pos end to ground and neg end to -vcc? do +vcc and -vcc magnitudes have to be equivalent for an op amp? It seems I will have to get some extra component either way…

Best Answer

If you only need a few mA the simplest solution is to use a charge pump like the ICL7660 to create -5V from +5V:

enter image description here

As you can see it only needs a few components. This simplicity has its price, and that's that the output voltage starts to drop if you load it with more than just a few mA.

Alternatively you can use an inverting SMPS (Switch-Mode Power Supply), like this one

LTC3631 app

which will allow for more current. The ratio R1/R2 sets the output voltage. This is the simplest switcher application I know. An SMPS however requires careful component selection and PCB layout to get a good efficiency and low EMI.

Related Solutions

Electronic – arduino – Why won’t the arduino board read an analog pin correctly

Try this code:

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  Serial.println(analogRead(0));
  delay(1000);
}

Load the serial monitor, set it to 9600 baud, and see what you get.

Electronic – Arduino serial communication produces noise on electret microphone

If this is indeed an issue of analog/digital separation there are a number of electrical strategies to overcoming it. The easiest of these is to have a separate ground plane for your analog circuitry from your digital cicuitry and join those ground planes at the common return (i.e. the power input to your board). This is called a star-ground topology. I'm not sure what you're going for with the diodes you mention in your question, but you might also consider filtering the VCC to your analog circuit through a ferrite bead and capacitor, and make sure you have adequate decoupling capacitors near all the VCC pins of your amplifiers and other analog circuits.

Best Answer

Related Solutions

Electronic – arduino – Why won’t the arduino board read an analog pin correctly

Electronic – Arduino serial communication produces noise on electret microphone

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