why input offset voltage exist in all op-amp? only i know it due to mismatch of input offset current. please ans and explain
They cannot make the input transistors in an opamp exactly the same. The small difference causes an input offset voltage and current. Some opamps have the input offset voltage and current almost eliminated by laser trimming of the emitter resistors.
The only way there would be no offset at all would be if the transistors were matched to perfection. Nothing made by man ever achieves perfection.....
