OP AMP - CONDITIONS FOR THE GOLDEN RULE

Is the golden rule always true? Are the two inputs always at the same voltage?

NO! These conditions must be true for the two inputs are within several tens of microvolts of each other.

• The output must not be saturated.
• The output must not be changing faster than the slew rate. This happens at higher frequencies and large output voltage changes.
• At hight frequencies the difference between the inputs increase with frequency.
• The feedback must be negative.