Open Loop Gain Revisited

By definition, an op-amp constructed without any feedback elements are said to be open-loop configuration. The open-loop gain (A) of an op-amp is the difference between the voltage signals applied at its two input terminals, i.e. V_OUT divided by, (V_IN+ - V_IN-), equals to A. i.e. A = V_OUT/(V_IN+ - V_IN-)

To realize the op-amp's open-loop gain, we can make a straight-line graph, which shows the transfer characteristic of a linear amplifier.