How to use op-amp with negative supply voltage?

Started by phuzle, January 15, 2010, 12:42:03 PM

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phuzle

I am trying to use a negative supply for my PNP germanium transistors, and I'm trying to create another circuit in the same box with a quad op-amp.  I want the op-amp to run on the same negative supply, so I don't have to use max1044 or anything to create a bipolar supply.  How to I wire my op-amp to work with this negative supply?  Pin 4 (Vcc) to -9?  And Pin 11 to ground? 

Or do I need a different kind of op-amp that is made for negative supply voltage?  Something that uses a Vee for -9?  In which case, what op-amps can I use?  Does smallbear have them?

slacker

On a quad opamp the positive supply goes to pin 4 and the negative supply goes to pin 11. The opamp doesn't really care what these voltages are so long as pin 4 is higher than pin 11 and the difference between them isn't more than maximum supply voltage.
So if you want to run it off your negative supply connect pin 4 to ground and pin 11 to -9 volts.