Abstract: An amplifier circuit contains a first and second current branch, each branch comprising an input transistor and a cascode transistor. Inputs of the amplifier are coupled to control electrodes of the input transistors in respective ones of the current branches. The control electrodes of the cascode transistors are coupled to each other. A high frequency coupling is provided between the control electrodes of the cascode transistors and a node of the common current source, to copy substantially common mode voltage changes of terminals of the main current channels of the input transistors to voltage changes at the control electrodes of the cascode transistors.