Virtual Grounding in Single Supply Op Amp Circuits
How does a designer operate an op amp from a single power supply voltage?
The designer needs to produce (or utilize) a potential that is half way between the power supply voltage and ground. Frequently, this potential already exists in the
system - as a Vref output from a data converter, for instance. The designer will only have to determine if the Vref that is available needs to be buffered.
If no source of Vcc/2 is available, then the designer must create it using the circuit below:
The opamp should be a low noise voltage feedback type.