Here is an example from a data-sheet of an opamp:
(At TA = +25°C, RL = 10 k connected to mid-supply, VCM = VOUT = mid-supply, unless otherwise noted. Boldface limits apply over the specified temperature range, TA = –40°C to 85°C, guaranteed by characterization and/or design.)
Does mid-supply mean ground for dual-supplies? And what does it mean for a single supply opamp?
For dual supplies that are symmetric, eg +/- 10v, mid-supply means ground.
When the supply pins of an op-amp are not symmetric about ground, for instance 0v and +5v for a single supply amp, or -4v and +12v for some arbitrary dual supply, then mid-supply means, well, mid-supply, +2.5v in the first example, +4v in the second.
A common way to get an 'RL of 10k connected to mid supply' is to use two 20k resistors, one connected to the -ve supply, one connected to the +ve supply.
