[HomeBrew] Another LM324 OP Amp question

[Steven Weber]

Op amps have a Postive voltage supply terminal and a negative voltage supply 
terminal. So long as the + supply terminal is postive in respect to the - 
supply terminal, it will work.

So, yes, if "ground" is 0 volts  and connected to the + supply terminal, 
the - supply terminal would need to be connected to a negative voltage and 
the output of the op amp will always be a negative voltage in respect to 
ground.

Of course, if you need both + and - output swing (in respect to ground), you 
use a +/- supply.

Steve KD1JV

>
> I was wondering that if I required only a negative voltage output if the 
> chip could be supplied with a negative voltage and ground instead of 
> positive.
>
> If so would you ground the normal + volts pin and feed the - volts to the 
> normal ground pin?