Single-Supply Circuit Collection Introduction Describing a Split-Supply Op Amp Circuit With Input Not Referenced To Ground
What happens when a split-supply op amp circuit is provided an input that is not referenced to ground?
When the signal source is not referenced to ground (see the figure below),
the voltage difference between ground and the reference voltage shows up amplified in
the output voltage. Sometimes this situation is OK, but other times the difference voltage
must be stripped out of the output voltage.
Refer to the following links:
Single-Supply Circuit Circuit Collection Introduction Describing The Split-Supply Topology
Single-Supply Circuit Collection Boundary Conditions
Single-Supply Circuit Collection Amplifiers