Operational amplifier

A continuous-time operational amplifier comprising:

• means for introducing an additional current to at least one internal node of said continuous-time operational amplifier for reducing an output offset voltage of said continuous-time operational amplifier;
• and
• a differential input stage and a second stage connected to each other, said means for introducing applying said additional current to a node of said differential input stage, wherein said differential input stage comprises a first, a second, a third and a fourth transistor, each of said first, second, third fourth transistor having a source, a gate and a drain, wherein said gates of said first and said second transistor are connected to different input terminals of said operational amplifier, wherein said sources of said first and said second transistor are connected to a supply voltage of said operational amplifier, wherein said sources of said third and said fourth transistor are connected to ground, wherein said drains of said first and said second transistor are connected to said drains of said third and said fourth transistor, respectively, wherein said gate and said drain of said third transistor are short-circuited to each other, wherein said connection between said drains of said second and said fourth transistor is connected to said second stage, and wherein said means for introducing an additional current apply said additional current to said connection between said drains of said first and said third transistor.